| Message ID | 20210901201934.1084250-1-dianders@chromium.org |
|---|---|
| Headers | show |
| Series | eDP: Support probing eDP panels dynamically instead of hardcoding | expand |
On Wed, Sep 1, 2021 at 1:20 PM Douglas Anderson <dianders@chromium.org> wrote: > > In the patch ("drm/panel-simple-edp: Split eDP panels out of > panel-simple") we split the PANEL_SIMPLE driver in 2. By default let's > give everyone who had the old driver enabled the new driver too. If > folks want to opt-out of one or the other they always can later. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> Isn't this a case where the new option should just have had the old option as the default value to avoid this kind of churn and possibly broken platforms? -Olof
Removed most CC: SMTP server protested. On 01.09.2021 22:19, Douglas Anderson wrote: > The goal of this patch series is to move away from hardcoding exact > eDP panels in device tree files. As discussed in the various patches > in this series (I'm not repeating everything here), most eDP panels > are 99% probable and we can get that last 1% by allowing two "power > up" delays to be specified in the device tree file and then using the > panel ID (found in the EDID) to look up additional power sequencing > delays for the panel. > > This patch series is the logical contiunation of a previous patch > series where I proposed solving this problem by adding a > board-specific compatible string [1]. In the discussion that followed > it sounded like people were open to something like the solution > proposed in this new series. > > In version 2 I got rid of the idea that we could have a "fallback" > compatible string that we'd use if we didn't recognize the ID in the > EDID. This simplifies the bindings a lot and the implementation > somewhat. As a result of not having a "fallback", though, I'm not > confident in transitioning any existing boards over to this since > we'll have to fallback to very conservative timings if we don't > recognize the ID from the EDID and I can't guarantee that I've seen > every panel that might have shipped on an existing product. The plan > is to use "edp-panel" only on new boards or new revisions of old > boards where we can guarantee that every EDID that ships out of the > factory has an ID in the table. > > Version 3 of this series now splits out all eDP panels to their own > driver and adds the generic eDP panel support to this new driver. I > believe this is what Sam was looking for [2]. > > [1] https://lore.kernel.org/r/YFKQaXOmOwYyeqvM@google.com/ > [2] https://lore.kernel.org/r/YRTsFNTn%2FT8fLxyB@ravnborg.org/ > I like the idea - if something can be configured dynamically lets do it. But I have few questions: 1. Have you read different real panels id's? In many cases (MIPI DSI, LVDS with EDID) manufacturers often forgot to set proper id fields. I do not know how EDID's ids are reliable in case of edp panels. 2. You are working with edp panels - beside EDID they have DPCD which contains things like IEEE_OUI and "Device Identification String", I guess they could be also used for detecting panels, have you considered it? I think DPCD Id should be assigned to EDP-Sink interface, and EDID Id to the actual panel behind it. With this assumption one could consider which timings should be property of which entity. Regards Andrzej
Hi, On Thu, Sep 2, 2021 at 3:10 PM Andrzej Hajda <a.hajda@samsung.com> wrote: > > Removed most CC: SMTP server protested. Yeah, it was because of the dang defconfig patches. My general policy is to send the cover letter to everyone even if not everyone gets CCed on all patches, but it ended up as a lot... Speaking of which, I'd definitely be interested in your take on the defconfig topic: https://lore.kernel.org/r/CAD=FV=WPXAUyuAHb1jKx9F_aw+JGX4MWB3or=Eq5rXoKY=OQMw@mail.gmail.com Do you agree with Olof that I should set the "default" for the new config to be the same as the old config? It doesn't make sense going forward but it helps for anyone with old configs... > On 01.09.2021 22:19, Douglas Anderson wrote: > > The goal of this patch series is to move away from hardcoding exact > > eDP panels in device tree files. As discussed in the various patches > > in this series (I'm not repeating everything here), most eDP panels > > are 99% probable and we can get that last 1% by allowing two "power > > up" delays to be specified in the device tree file and then using the > > panel ID (found in the EDID) to look up additional power sequencing > > delays for the panel. > > > > This patch series is the logical contiunation of a previous patch > > series where I proposed solving this problem by adding a > > board-specific compatible string [1]. In the discussion that followed > > it sounded like people were open to something like the solution > > proposed in this new series. > > > > In version 2 I got rid of the idea that we could have a "fallback" > > compatible string that we'd use if we didn't recognize the ID in the > > EDID. This simplifies the bindings a lot and the implementation > > somewhat. As a result of not having a "fallback", though, I'm not > > confident in transitioning any existing boards over to this since > > we'll have to fallback to very conservative timings if we don't > > recognize the ID from the EDID and I can't guarantee that I've seen > > every panel that might have shipped on an existing product. The plan > > is to use "edp-panel" only on new boards or new revisions of old > > boards where we can guarantee that every EDID that ships out of the > > factory has an ID in the table. > > > > Version 3 of this series now splits out all eDP panels to their own > > driver and adds the generic eDP panel support to this new driver. I > > believe this is what Sam was looking for [2]. > > > > [1] https://lore.kernel.org/r/YFKQaXOmOwYyeqvM@google.com/ > > [2] https://lore.kernel.org/r/YRTsFNTn%2FT8fLxyB@ravnborg.org/ > > > I like the idea - if something can be configured dynamically lets do it. > But I have few questions: > 1. Have you read different real panels id's? In many cases (MIPI DSI, > LVDS with EDID) manufacturers often forgot to set proper id fields. I do > not know how EDID's ids are reliable in case of edp panels. I have read several and (so far) they have been quite reliable but I will admit that I haven't done an exhaustive sample. I guess my answer to whether we can trust it is: a) Presumably you'd only use this new "edp-panel" compatible on systems whose panel IDs are known to be reliable. Old systems can keep determining the panel by compatible string. The two schemes can co-exist. b) As we start using this new scheme then there will be more validation of panel ID strings and, presumably, they will become more reliable. It is still true that ID conflicts could exist. A vendor could ship two different panels with the same ID and maybe nobody would notice because they weren't ever hooked up to the same board. In that case we'd have a question of what to do upstream. If this really happens then I suppose (worst case) we could use the device tree to help differentiate and each board could say that "panel ID <x> hooked up to this board is actually panel <y>". I hope we don't have to do that because it feels dirty, but at least it gives us _something_ if we get backed into a corner. > 2. You are working with edp panels - beside EDID they have DPCD which > contains things like IEEE_OUI and "Device Identification String", I > guess they could be also used for detecting panels, have you considered > it? I think DPCD Id should be assigned to EDP-Sink interface, and EDID > Id to the actual panel behind it. With this assumption one could > consider which timings should be property of which entity. This could be another way to help us if we're backed into a corner in the future. Right now the driver requires that you give access to a full eDP AUX bus to use the "generic eDP" panel support even though it currently only relies on the EDID, so it would be pretty easy to utilize this info in the future. So far the ID has been reliable for me though. -Doug
On 02.09.2021 01:10, Doug Anderson wrote: > Hi, > > On Wed, Sep 1, 2021 at 2:12 PM Olof Johansson <olof@lixom.net> wrote: >> >> On Wed, Sep 1, 2021 at 1:20 PM Douglas Anderson <dianders@chromium.org> wrote: >>> >>> In the patch ("drm/panel-simple-edp: Split eDP panels out of >>> panel-simple") we split the PANEL_SIMPLE driver in 2. By default let's >>> give everyone who had the old driver enabled the new driver too. If >>> folks want to opt-out of one or the other they always can later. >>> >>> Signed-off-by: Douglas Anderson <dianders@chromium.org> >> >> Isn't this a case where the new option should just have had the old >> option as the default value to avoid this kind of churn and possibly >> broken platforms? > > I'm happy to go either way. I guess I didn't do that originally > because logically there's not any reason to link the two drivers going > forward. Said another way, someone enabling the "simple panel" driver > for non-eDP panels wouldn't expect that the "simple panel" driver for > DP panels would also get enabled by default. They really have nothing > to do with one another. Enabling by default for something like this > also seems like it would lead to bloat. I could have sworn that > periodically people get yelled at for marking drivers on by default > when it doesn't make sense. > > ...that being said, I'm happy to change the default as you suggest. > Just let me know. I guess this is just misunderstanding. Symbol names: CONFIG_DRM_PANEL_SIMPLE=y CONFIG_DRM_PANEL_SIMPLE_EDP=y suggests that CONFIG_DRM_PANEL_SIMPLE_EDP is an 'suboption' of CONFIG_DRM_PANEL_SIMPLE, but these symbols are independent - old symbol has been split into two independent new symbols. So Doug's approach seems correct to me. Maybe one could change names of symbols to avoid confusion(?). One more thing, I suspect previous patch can break platforms with EDP panels. Even if this patch fixes it, maybe it would be better to squash these patches? Or add temporal solution to save bisecatability. Regards Andrzej > > -Doug >
On Wed, 01 Sep 2021, Douglas Anderson <dianders@chromium.org> wrote: > A future change wants to be able to read just block 0 of the EDID, so > break it out of drm_do_get_edid() into a sub-function. > > This is intended to be a no-op change--just code movement. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > > (no changes since v1) > > drivers/gpu/drm/drm_edid.c | 62 +++++++++++++++++++++++++++----------- > 1 file changed, 44 insertions(+), 18 deletions(-) > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > index 6325877c5fd6..a22c38482a90 100644 > --- a/drivers/gpu/drm/drm_edid.c > +++ b/drivers/gpu/drm/drm_edid.c > @@ -1905,6 +1905,43 @@ int drm_add_override_edid_modes(struct drm_connector *connector) > } > EXPORT_SYMBOL(drm_add_override_edid_modes); > > +static struct edid *drm_do_get_edid_blk0( Maybe base_block instead of blk0? > + int (*get_edid_block)(void *data, u8 *buf, unsigned int block, > + size_t len), > + void *data, bool *edid_corrupt, int *null_edid_counter) > +{ > + int i; > + u8 *edid; With void *edid, this function wouldn't need the cast internally. > + > + if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL) > + return NULL; Could split the allocation and NULL check to two separate lines per coding style, while at it? BR, Jani. > + > + /* base block fetch */ > + for (i = 0; i < 4; i++) { > + if (get_edid_block(data, edid, 0, EDID_LENGTH)) > + goto out; > + if (drm_edid_block_valid(edid, 0, false, edid_corrupt)) > + break; > + if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) { > + if (null_edid_counter) > + (*null_edid_counter)++; > + goto carp; > + } > + } > + if (i == 4) > + goto carp; > + > + return (struct edid *)edid; > + > +carp: > + kfree(edid); > + return ERR_PTR(-EINVAL); > + > +out: > + kfree(edid); > + return NULL; > +} > + > /** > * drm_do_get_edid - get EDID data using a custom EDID block read function > * @connector: connector we're probing > @@ -1938,25 +1975,16 @@ struct edid *drm_do_get_edid(struct drm_connector *connector, > if (override) > return override; > > - if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL) > + edid = (u8 *)drm_do_get_edid_blk0(get_edid_block, data, > + &connector->edid_corrupt, > + &connector->null_edid_counter); > + if (IS_ERR_OR_NULL(edid)) { > + if (IS_ERR(edid)) > + connector_bad_edid(connector, edid, 1); > return NULL; > - > - /* base block fetch */ > - for (i = 0; i < 4; i++) { > - if (get_edid_block(data, edid, 0, EDID_LENGTH)) > - goto out; > - if (drm_edid_block_valid(edid, 0, false, > - &connector->edid_corrupt)) > - break; > - if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) { > - connector->null_edid_counter++; > - goto carp; > - } > } > - if (i == 4) > - goto carp; > > - /* if there's no extensions, we're done */ > + /* if there's no extensions or no connector, we're done */ > valid_extensions = edid[0x7e]; > if (valid_extensions == 0) > return (struct edid *)edid; > @@ -2010,8 +2038,6 @@ struct edid *drm_do_get_edid(struct drm_connector *connector, > > return (struct edid *)edid; > > -carp: > - connector_bad_edid(connector, edid, 1); > out: > kfree(edid); > return NULL; -- Jani Nikula, Intel Open Source Graphics Center
Hi, On Fri, Sep 3, 2021 at 1:38 PM Stephen Boyd <sboyd@kernel.org> wrote: > > Quoting Doug Anderson (2021-09-01 16:10:15) > > Hi, > > > > On Wed, Sep 1, 2021 at 2:12 PM Olof Johansson <olof@lixom.net> wrote: > > > > > > On Wed, Sep 1, 2021 at 1:20 PM Douglas Anderson <dianders@chromium.org> wrote: > > > > > > > > In the patch ("drm/panel-simple-edp: Split eDP panels out of > > > > panel-simple") we split the PANEL_SIMPLE driver in 2. By default let's > > > > give everyone who had the old driver enabled the new driver too. If > > > > folks want to opt-out of one or the other they always can later. > > > > > > > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > > > > > > Isn't this a case where the new option should just have had the old > > > option as the default value to avoid this kind of churn and possibly > > > broken platforms? > > > > I'm happy to go either way. I guess I didn't do that originally > > because logically there's not any reason to link the two drivers going > > forward. Said another way, someone enabling the "simple panel" driver > > for non-eDP panels wouldn't expect that the "simple panel" driver for > > DP panels would also get enabled by default. They really have nothing > > to do with one another. Enabling by default for something like this > > also seems like it would lead to bloat. I could have sworn that > > periodically people get yelled at for marking drivers on by default > > when it doesn't make sense. > > > > ...that being said, I'm happy to change the default as you suggest. > > Just let me know. > > Having the default will help olddefconfig users seamlessly migrate to > the new Kconfig. Sadly they don't notice that they should probably > disable the previous Kconfig symbol, but oh well. At least with the > default they don't go on a hunt/bisect to figure out that some Kconfig > needed to be enabled now that they're using a new kernel version. > > Maybe the default should have a TODO comment next to it indicating we > should remove the default in a year or two. OK, so I'm trying to figure out how to do this without just "kicking the can" down the road. I guess your idea is that for the next year this will be the default and that anyone who really wants "CONFIG_DRM_PANEL_EDP" will "opt-in" to keep it by adding "CONFIG_DRM_PANEL_EDP=y" to their config? ...and then after a year passes we remove the default? ...but that won't work, will it? Since "CONFIG_DRM_PANEL_EDP" will be the default for the next year then you really can't add it to the "defconfig", at least if you ever "normalize" it. The "defconfig" by definition has everything stripped from it that's already the "default", so for the next year anyone who tries to opt-in will get their preference stripped. Hrm, so let me explain options as I see them. Maybe someone can point out something that I missed. I'll assume that we'll change the config option from CONFIG_DRM_PANEL_SIMPLE_EDP to CONFIG_DRM_PANEL_EDP (remove the "SIMPLE" part). == Where we were before my series: * One config "CONFIG_DRM_PANEL_SIMPLE" and it enables simple non-eDP and eDP drivers. == Option 1: update everyone's configs (this patch) * Keep old config "CONFIG_DRM_PANEL_SIMPLE" but it now only means enable the panel-simple (non-eDP) driver. * Anyone who wants eDP panels must opt-in to "CONFIG_DRM_PANEL_EDP" * Update all configs in mainline; any out-of mainline configs must figure this out themselves. Pros: * no long term baggage Cons: * patch upstream is a bit of "churn" * anyone with downstream config will have to figure out what happened. == Option 2: kick the can down the road + accept cruft * Keep old config "CONFIG_DRM_PANEL_SIMPLE" and it means enable the panel-simple (non-eDP) driver. * Anyone with "CONFIG_DRM_PANEL_SIMPLE" is opted in by default to "CONFIG_DRM_PANEL_EDP" AKA: config DRM_PANEL_EDP default DRM_PANEL_SIMPLE Pros: * no config patches needed upstream at all and everything just works! Cons: * people are opted in to extra cruft by default and need to know to turn it off. * unclear if we can change the default without the same problems. == Option 3: try to be clever * Add _two_ new configs. CONFIG_DRM_PANEL_SIMPLE_V2 and CONFIG_DRM_PANEL_EDP. * Old config "CONFIG_DRM_PANEL_SIMPLE" gets marked as "deprecated". * Both new configs have "default CONFIG_DRM_PANEL_SIMPLE" Now anyone old will magically get both the new config options by default. Anyone looking at this in the future _won't_ set the deprecated CONFIG_DRM_PANEL_SIMPLE but will instead choose if they want either the eDP or "simple" driver. Pros: * No long term baggage. * Everyone is transitioned automatically by default with no cruft patches. Cons: * I can't think of a better name than "CONFIG_DRM_PANEL_SIMPLE_V2" and that name is ugly. == Option 4: shave a yak When thinking about this I came up with a clever idea of stashing the kernel version in a defconfig when it's generated. Then you could do something like: config DRM_PANEL_EDP default DRM_PANEL_SIMPLE if DEFCONFIG_GENERATED_AT <= 0x00050f00 That feels like a good idea to me but who knows what others would think. In general I think this series already shaves enough yaks. This isn't a new problem we're trying to solve so it seems like we should pick one of the options above. == Unless I get an explicit NAK from someone like Olof or Arnd or I hear that everyone loves Option #3 I'll probably just stick with the existing approach since: * Olof's wording didn't make it sound like a strong objection. * From git history it looks as if config patches don't necessarily land through the SoC tree and thus I'd by default follow the suggestions of the DRM folks. Andrzej suggested going with the existing approach as long as I changed the symbol names and re-ordered the patches. Please yell if anything above sounds wrong! I'll probably try to send out a new version tomorrow or the next day, but I won't land it right away to give people time to yell. -Doug
On Wed, Sep 8, 2021 at 3:36 PM Doug Anderson <dianders@chromium.org> wrote: > > Hi, > > On Fri, Sep 3, 2021 at 1:38 PM Stephen Boyd <sboyd@kernel.org> wrote: > > > > Quoting Doug Anderson (2021-09-01 16:10:15) > > > Hi, > > > > > > On Wed, Sep 1, 2021 at 2:12 PM Olof Johansson <olof@lixom.net> wrote: > > > > > > > > On Wed, Sep 1, 2021 at 1:20 PM Douglas Anderson <dianders@chromium.org> wrote: > > > > > > > > > > In the patch ("drm/panel-simple-edp: Split eDP panels out of > > > > > panel-simple") we split the PANEL_SIMPLE driver in 2. By default let's > > > > > give everyone who had the old driver enabled the new driver too. If > > > > > folks want to opt-out of one or the other they always can later. > > > > > > > > > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > > > > > > > > Isn't this a case where the new option should just have had the old > > > > option as the default value to avoid this kind of churn and possibly > > > > broken platforms? > > > > > > I'm happy to go either way. I guess I didn't do that originally > > > because logically there's not any reason to link the two drivers going > > > forward. Said another way, someone enabling the "simple panel" driver > > > for non-eDP panels wouldn't expect that the "simple panel" driver for > > > DP panels would also get enabled by default. They really have nothing > > > to do with one another. Enabling by default for something like this > > > also seems like it would lead to bloat. I could have sworn that > > > periodically people get yelled at for marking drivers on by default > > > when it doesn't make sense. > > > > > > ...that being said, I'm happy to change the default as you suggest. > > > Just let me know. > > > > Having the default will help olddefconfig users seamlessly migrate to > > the new Kconfig. Sadly they don't notice that they should probably > > disable the previous Kconfig symbol, but oh well. At least with the > > default they don't go on a hunt/bisect to figure out that some Kconfig > > needed to be enabled now that they're using a new kernel version. > > > > Maybe the default should have a TODO comment next to it indicating we > > should remove the default in a year or two. > > OK, so I'm trying to figure out how to do this without just "kicking > the can" down the road. I guess your idea is that for the next year > this will be the default and that anyone who really wants > "CONFIG_DRM_PANEL_EDP" will "opt-in" to keep it by adding > "CONFIG_DRM_PANEL_EDP=y" to their config? ...and then after a year > passes we remove the default? ...but that won't work, will it? Since > "CONFIG_DRM_PANEL_EDP" will be the default for the next year then you > really can't add it to the "defconfig", at least if you ever > "normalize" it. The "defconfig" by definition has everything stripped > from it that's already the "default", so for the next year anyone who > tries to opt-in will get their preference stripped. > > Hrm, so let me explain options as I see them. Maybe someone can point > out something that I missed. I'll assume that we'll change the config > option from CONFIG_DRM_PANEL_SIMPLE_EDP to CONFIG_DRM_PANEL_EDP > (remove the "SIMPLE" part). > > == > > Where we were before my series: > > * One config "CONFIG_DRM_PANEL_SIMPLE" and it enables simple non-eDP > and eDP drivers. > > == > > Option 1: update everyone's configs (this patch) > > * Keep old config "CONFIG_DRM_PANEL_SIMPLE" but it now only means > enable the panel-simple (non-eDP) driver. > * Anyone who wants eDP panels must opt-in to "CONFIG_DRM_PANEL_EDP" > * Update all configs in mainline; any out-of mainline configs must > figure this out themselves. > > Pros: > * no long term baggage > > Cons: > * patch upstream is a bit of "churn" > * anyone with downstream config will have to figure out what happened. > > == > > Option 2: kick the can down the road + accept cruft > > * Keep old config "CONFIG_DRM_PANEL_SIMPLE" and it means enable the > panel-simple (non-eDP) driver. > * Anyone with "CONFIG_DRM_PANEL_SIMPLE" is opted in by default to > "CONFIG_DRM_PANEL_EDP" > > AKA: > config DRM_PANEL_EDP > default DRM_PANEL_SIMPLE > > Pros: > * no config patches needed upstream at all and everything just works! > > Cons: > * people are opted in to extra cruft by default and need to know to turn it off. > * unclear if we can change the default without the same problems. > > == > > Option 3: try to be clever > > * Add _two_ new configs. CONFIG_DRM_PANEL_SIMPLE_V2 and CONFIG_DRM_PANEL_EDP. > * Old config "CONFIG_DRM_PANEL_SIMPLE" gets marked as "deprecated". > * Both new configs have "default CONFIG_DRM_PANEL_SIMPLE" > > Now anyone old will magically get both the new config options by > default. Anyone looking at this in the future _won't_ set the > deprecated CONFIG_DRM_PANEL_SIMPLE but will instead choose if they > want either the eDP or "simple" driver. > > Pros: > * No long term baggage. > * Everyone is transitioned automatically by default with no cruft patches. > > Cons: > * I can't think of a better name than "CONFIG_DRM_PANEL_SIMPLE_V2" and > that name is ugly. > > == > > Option 4: shave a yak > > When thinking about this I came up with a clever idea of stashing the > kernel version in a defconfig when it's generated. Then you could do > something like: > > config DRM_PANEL_EDP > default DRM_PANEL_SIMPLE if DEFCONFIG_GENERATED_AT <= 0x00050f00 > > That feels like a good idea to me but who knows what others would > think. In general I think this series already shaves enough yaks. This > isn't a new problem we're trying to solve so it seems like we should > pick one of the options above. > > == > > Unless I get an explicit NAK from someone like Olof or Arnd or I hear > that everyone loves Option #3 I'll probably just stick with the > existing approach since: > > * Olof's wording didn't make it sound like a strong objection. Yeah, not a strong objection but an enquiry if there's a better way to handle it. TL;DR: I don't think there really is. My comment mostly came from the fact that when olddefconfig gets broken like this, we tend to have a bunch of patches trickle in over time as downstream users discover the need to turn on the new option. You covered (most) of that by doing the appropriate defconfigs to this patch series, so it won't be as bad (besides any newly added defconfigs during the same release, and we're quite careful about doing that these days). I think most of the other options, besides 2, are just more overhead than needed here. So I'd be fine with just picking up option 1. What's clear is that this is not a very convenient activity that scales, but we don't do it all that often. This is where something like a "HAVE_EDP" type config that the platform can provide helps, but adding it just for this rework seems to be more work than it's worth. > * From git history it looks as if config patches don't necessarily > land through the SoC tree and thus I'd by default follow the > suggestions of the DRM folks. Andrzej suggested going with the > existing approach as long as I changed the symbol names and re-ordered > the patches. Right, Kconfig changes usually go with the driver. dts and defconfig changes go to the SoC tree though since otherwise we end up with a bunch of churn and conflicts. > Please yell if anything above sounds wrong! I'll probably try to send > out a new version tomorrow or the next day, but I won't land it right > away to give people time to yell. I'd leave it up to you if you want to do option 1 or 2, since there's no really convenient way to do it better. 3 seems to be a bigger hammer than what this situation calls for IMHO. -Olof
Hi, On Sun, Sep 5, 2021 at 11:55 AM Sam Ravnborg <sam@ravnborg.org> wrote: > > Hi Douglas, > > On Wed, Sep 01, 2021 at 01:19:18PM -0700, Douglas Anderson wrote: > > The goal of this patch series is to move away from hardcoding exact > > eDP panels in device tree files. As discussed in the various patches > > in this series (I'm not repeating everything here), most eDP panels > > are 99% probable and we can get that last 1% by allowing two "power > > up" delays to be specified in the device tree file and then using the > > panel ID (found in the EDID) to look up additional power sequencing > > delays for the panel. > > > > This patch series is the logical contiunation of a previous patch > > series where I proposed solving this problem by adding a > > board-specific compatible string [1]. In the discussion that followed > > it sounded like people were open to something like the solution > > proposed in this new series. > > > > In version 2 I got rid of the idea that we could have a "fallback" > > compatible string that we'd use if we didn't recognize the ID in the > > EDID. This simplifies the bindings a lot and the implementation > > somewhat. As a result of not having a "fallback", though, I'm not > > confident in transitioning any existing boards over to this since > > we'll have to fallback to very conservative timings if we don't > > recognize the ID from the EDID and I can't guarantee that I've seen > > every panel that might have shipped on an existing product. The plan > > is to use "edp-panel" only on new boards or new revisions of old > > boards where we can guarantee that every EDID that ships out of the > > factory has an ID in the table. > > > > Version 3 of this series now splits out all eDP panels to their own > > driver and adds the generic eDP panel support to this new driver. I > > believe this is what Sam was looking for [2]. > > > > [1] https://lore.kernel.org/r/YFKQaXOmOwYyeqvM@google.com/ > > [2] https://lore.kernel.org/r/YRTsFNTn%2FT8fLxyB@ravnborg.org/ > > > > Changes in v3: > > - Decode hex product ID w/ same endianness as everyone else. > > - ("Reorder logicpd_type_28...") patch new for v3. > > - Split eDP panels patch new for v3. > > - Move wayward panels patch new for v3. > > - ("Non-eDP panels don't need "HPD" handling") new for v3. > > - Split the delay structure out patch just on eDP now. > > - ("Better describe eDP panel delays") new for v3. > > - Fix "prepare_to_enable" patch new for v3. > > - ("Don't re-read the EDID every time") moved to eDP only patch. > > - Generic "edp-panel" handled by the eDP panel driver now. > > - Change init order to we power at the end. > > - Adjust endianness of product ID. > > - Fallback to conservative delays if panel not recognized. > > - Add Sharp LQ116M1JW10 to table. > > - Add AUO B116XAN06.1 to table. > > - Rename delays more generically so they can be reused. > > > > Changes in v2: > > - No longer allow fallback to panel-simple. > > - Add "-ms" suffix to delays. > > - Don't support a "fallback" panel. Probed panels must be probed. > > - Not based on patch to copy "desc"--just allocate for probed panels. > > - Add "-ms" suffix to delays. > > > > Douglas Anderson (16): > > dt-bindings: drm/panel-simple-edp: Introduce generic eDP panels > > drm/edid: Break out reading block 0 of the EDID > > drm/edid: Allow the querying/working with the panel ID from the EDID > > drm/panel-simple: Reorder logicpd_type_28 / mitsubishi_aa070mc01 > > drm/panel-simple-edp: Split eDP panels out of panel-simple > > ARM: configs: Everyone who had PANEL_SIMPLE now gets PANEL_SIMPLE_EDP > > arm64: defconfig: Everyone who had PANEL_SIMPLE now gets > > PANEL_SIMPLE_EDP > > MIPS: configs: Everyone who had PANEL_SIMPLE now gets PANEL_SIMPLE_EDP > > drm/panel-simple-edp: Move some wayward panels to the eDP driver > > drm/panel-simple: Non-eDP panels don't need "HPD" handling > > drm/panel-simple-edp: Split the delay structure out > > drm/panel-simple-edp: Better describe eDP panel delays > > drm/panel-simple-edp: hpd_reliable shouldn't be subtraced from > > hpd_absent > > drm/panel-simple-edp: Fix "prepare_to_enable" if panel doesn't handle > > HPD > > drm/panel-simple-edp: Don't re-read the EDID every time we power off > > the panel > > drm/panel-simple-edp: Implement generic "edp-panel"s probed by EDID > > Thanks for looking into this. I really like the outcome. > We have panel-simple that now (mostly) handle simple panels, > and thus all the eDP functionality is in a separate driver. > > I have provided a few nits. > My only take on this is the naming - as we do not want to confuse > panel-simple and panel-edp I strongly suggest renaming the driver to > panel-edp. Sure, I'll do that. I was trying to express the fact that the new "panel-edp" driver won't actually handle _all_ eDP panels, only the eDP panels that are (comparatively) simpler. For instance, I'm not planning to handle panel-samsung-atna33xc20.c in "panel-edp". I guess people will figure it out, though. > And then rename the corresponding Kconfig entry. > > With these few changes all patches are: > Acked-by: Sam Ravnborg <sam@ravnborg.org> Thanks, I'll add it to the patches. If there's anything major I need to change I'll give you a yell to make sure you see it. > For bisectability I suggest to move the defconfig patches up before you > introduce the new Kconfig symbol. Or maybe they will be added via > another tree and then this is not possible to control Yup, I'll do that. There was some question about the defconfig patch but they are hopefully cleared up now. > I assume you will apply the patches yourself. Sure, I can do that with your Ack. I'll also make sure that patches that Jani commented on get resolved. -Doug
Hi, On Wed, Sep 1, 2021 at 1:20 PM Douglas Anderson <dianders@chromium.org> wrote: > > The "logicpd_type_28" panel data was splitting up the > mitsubishi_aa070mc01 panel data. Reorganize it so that the panel descs > and modes are kept together. > > This is a no-op code-cleanup change, found by code inspection. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > > Changes in v3: > - ("Reorder logicpd_type_28...") patch new for v3. > > drivers/gpu/drm/panel/panel-simple.c | 26 +++++++++++++------------- > 1 file changed, 13 insertions(+), 13 deletions(-) I've pushed just this one patch (with Sam's Ack from the cover letter) just to simplify future posts. It's pretty much a no-brainer patch and there are no dependencies anywhere for it. c8527b9ad3cf (drm-misc/drm-misc-next) drm/panel-simple: Reorder logicpd_type_28 / mitsubishi_aa070mc01 -Doug
The goal of this patch series is to move away from hardcoding exact eDP panels in device tree files. As discussed in the various patches in this series (I'm not repeating everything here), most eDP panels are 99% probable and we can get that last 1% by allowing two "power up" delays to be specified in the device tree file and then using the panel ID (found in the EDID) to look up additional power sequencing delays for the panel. This patch series is the logical contiunation of a previous patch series where I proposed solving this problem by adding a board-specific compatible string [1]. In the discussion that followed it sounded like people were open to something like the solution proposed in this new series. In version 2 I got rid of the idea that we could have a "fallback" compatible string that we'd use if we didn't recognize the ID in the EDID. This simplifies the bindings a lot and the implementation somewhat. As a result of not having a "fallback", though, I'm not confident in transitioning any existing boards over to this since we'll have to fallback to very conservative timings if we don't recognize the ID from the EDID and I can't guarantee that I've seen every panel that might have shipped on an existing product. The plan is to use "edp-panel" only on new boards or new revisions of old boards where we can guarantee that every EDID that ships out of the factory has an ID in the table. Version 3 of this series now splits out all eDP panels to their own driver and adds the generic eDP panel support to this new driver. I believe this is what Sam was looking for [2]. [1] https://lore.kernel.org/r/YFKQaXOmOwYyeqvM@google.com/ [2] https://lore.kernel.org/r/YRTsFNTn%2FT8fLxyB@ravnborg.org/ Changes in v3: - Decode hex product ID w/ same endianness as everyone else. - ("Reorder logicpd_type_28...") patch new for v3. - Split eDP panels patch new for v3. - Move wayward panels patch new for v3. - ("Non-eDP panels don't need "HPD" handling") new for v3. - Split the delay structure out patch just on eDP now. - ("Better describe eDP panel delays") new for v3. - Fix "prepare_to_enable" patch new for v3. - ("Don't re-read the EDID every time") moved to eDP only patch. - Generic "edp-panel" handled by the eDP panel driver now. - Change init order to we power at the end. - Adjust endianness of product ID. - Fallback to conservative delays if panel not recognized. - Add Sharp LQ116M1JW10 to table. - Add AUO B116XAN06.1 to table. - Rename delays more generically so they can be reused. Changes in v2: - No longer allow fallback to panel-simple. - Add "-ms" suffix to delays. - Don't support a "fallback" panel. Probed panels must be probed. - Not based on patch to copy "desc"--just allocate for probed panels. - Add "-ms" suffix to delays. Douglas Anderson (16): dt-bindings: drm/panel-simple-edp: Introduce generic eDP panels drm/edid: Break out reading block 0 of the EDID drm/edid: Allow the querying/working with the panel ID from the EDID drm/panel-simple: Reorder logicpd_type_28 / mitsubishi_aa070mc01 drm/panel-simple-edp: Split eDP panels out of panel-simple ARM: configs: Everyone who had PANEL_SIMPLE now gets PANEL_SIMPLE_EDP arm64: defconfig: Everyone who had PANEL_SIMPLE now gets PANEL_SIMPLE_EDP MIPS: configs: Everyone who had PANEL_SIMPLE now gets PANEL_SIMPLE_EDP drm/panel-simple-edp: Move some wayward panels to the eDP driver drm/panel-simple: Non-eDP panels don't need "HPD" handling drm/panel-simple-edp: Split the delay structure out drm/panel-simple-edp: Better describe eDP panel delays drm/panel-simple-edp: hpd_reliable shouldn't be subtraced from hpd_absent drm/panel-simple-edp: Fix "prepare_to_enable" if panel doesn't handle HPD drm/panel-simple-edp: Don't re-read the EDID every time we power off the panel drm/panel-simple-edp: Implement generic "edp-panel"s probed by EDID .../bindings/display/panel/panel-edp.yaml | 188 ++ arch/arm/configs/at91_dt_defconfig | 1 + arch/arm/configs/exynos_defconfig | 1 + arch/arm/configs/imx_v6_v7_defconfig | 1 + arch/arm/configs/lpc32xx_defconfig | 1 + arch/arm/configs/multi_v5_defconfig | 1 + arch/arm/configs/multi_v7_defconfig | 1 + arch/arm/configs/omap2plus_defconfig | 1 + arch/arm/configs/qcom_defconfig | 1 + arch/arm/configs/realview_defconfig | 1 + arch/arm/configs/sama5_defconfig | 1 + arch/arm/configs/shmobile_defconfig | 1 + arch/arm/configs/sunxi_defconfig | 1 + arch/arm/configs/tegra_defconfig | 1 + arch/arm/configs/versatile_defconfig | 1 + arch/arm/configs/vexpress_defconfig | 1 + arch/arm64/configs/defconfig | 1 + arch/mips/configs/qi_lb60_defconfig | 1 + arch/mips/configs/rs90_defconfig | 1 + drivers/gpu/drm/drm_edid.c | 121 +- drivers/gpu/drm/panel/Kconfig | 16 +- drivers/gpu/drm/panel/Makefile | 1 + drivers/gpu/drm/panel/panel-simple-edp.c | 1895 +++++++++++++++++ drivers/gpu/drm/panel/panel-simple.c | 1100 +--------- include/drm/drm_edid.h | 47 + 25 files changed, 2293 insertions(+), 1093 deletions(-) create mode 100644 Documentation/devicetree/bindings/display/panel/panel-edp.yaml create mode 100644 drivers/gpu/drm/panel/panel-simple-edp.c