| Message ID | 20240108183302.255055-5-afd@ti.com |
|---|---|
| State | New |
| Headers | show |
| Series | Device tree support for Imagination Series5 GPU | expand |
Hi, I just comment on this example, but it applies almost the same for all other .dtsi changes. > Am 08.01.2024 um 19:32 schrieb Andrew Davis <afd@ti.com>: > > Add SGX GPU device entry to base OMAP4 dtsi file. > > Signed-off-by: Andrew Davis <afd@ti.com> > --- > arch/arm/boot/dts/ti/omap/omap4.dtsi | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/boot/dts/ti/omap/omap4.dtsi b/arch/arm/boot/dts/ti/omap/omap4.dtsi > index 2bbff9032be3e..559b2bfe4ca7c 100644 > --- a/arch/arm/boot/dts/ti/omap/omap4.dtsi > +++ b/arch/arm/boot/dts/ti/omap/omap4.dtsi > @@ -501,10 +501,11 @@ sgx_module: target-module@56000000 { > #size-cells = <1>; > ranges = <0 0x56000000 0x2000000>; > > - /* > - * Closed source PowerVR driver, no child device > - * binding or driver in mainline > - */ > + gpu@0 { I wonder why we don't add a "gpu:" label here. Almost all other subsystem nodes have one (e.g. emif:, aes:, dss:, dsi:, hdmi:, etc.), obviously for convenience when using a .dtsi file. It would allow a board-specific DTS to easily add status = "disabled" to avoid driver probing or disabling the GPU (e.g. if there is no display). > + compatible = "ti,omap4430-gpu", "img,powervr-sgx540"; It still appears to me that the "img,powervr-sgx540" (or similar) entry is redundant information. I have experimentally updated our openpvrsgx driver and we do not have any use for this information (at least in the kernel driver): https://github.com/goldelico/letux-kernel/commit/f2f7cb3b858ef255f52f2b82a8bb34c047337afe It shows how easy it is to derive the sgx version and revision number if we ever need it inside the driver. So if you want to keep a reference to powervr, it would suffice to have > + compatible = "ti,omap4430-gpu", "img,powervr-sgx"; Otherwise your device tree entries compile fine and seem to work (at least in a cursory test on PandaBoard ES). > + reg = <0x0 0x2000000>; /* 32MB */ > + interrupts = <GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>; > + }; > }; BR and thanks, Nikolaus
Hi, On Fri, Jan 12, 2024 at 06:33:58PM +0100, H. Nikolaus Schaller wrote: > > Am 08.01.2024 um 19:32 schrieb Andrew Davis <afd@ti.com>: > > > > Add SGX GPU device entry to base OMAP4 dtsi file. > > > > Signed-off-by: Andrew Davis <afd@ti.com> > > --- > > arch/arm/boot/dts/ti/omap/omap4.dtsi | 9 +++++---- > > 1 file changed, 5 insertions(+), 4 deletions(-) > > > > diff --git a/arch/arm/boot/dts/ti/omap/omap4.dtsi b/arch/arm/boot/dts/ti/omap/omap4.dtsi > > index 2bbff9032be3e..559b2bfe4ca7c 100644 > > --- a/arch/arm/boot/dts/ti/omap/omap4.dtsi > > +++ b/arch/arm/boot/dts/ti/omap/omap4.dtsi > > @@ -501,10 +501,11 @@ sgx_module: target-module@56000000 { > > #size-cells = <1>; > > ranges = <0 0x56000000 0x2000000>; > > > > - /* > > - * Closed source PowerVR driver, no child device > > - * binding or driver in mainline > > - */ > > + gpu@0 { > > I wonder why we don't add a "gpu:" label here. > > Almost all other subsystem nodes have one (e.g. emif:, aes:, dss:, dsi:, hdmi:, etc.), > obviously for convenience when using a .dtsi file. > > It would allow a board-specific DTS to easily add status = "disabled" to avoid driver > probing or disabling the GPU (e.g. if there is no display). There's no reason to disable it in the DT: the hardware block would still be there and it's rendering to memory so it still could be useful. If there's no display on the board and you really don't want the GPU driver, then you can disable the driver or block the module loading, but it should be a distro / package / user decision, not a DT / kernel one still. Maxime
Hi, > Am 15.01.2024 um 09:25 schrieb Maxime Ripard <mripard@kernel.org>: > > Hi, > > On Fri, Jan 12, 2024 at 06:33:58PM +0100, H. Nikolaus Schaller wrote: >>> Am 08.01.2024 um 19:32 schrieb Andrew Davis <afd@ti.com>: >>> >>> Add SGX GPU device entry to base OMAP4 dtsi file. >>> >>> Signed-off-by: Andrew Davis <afd@ti.com> >>> --- >>> arch/arm/boot/dts/ti/omap/omap4.dtsi | 9 +++++---- >>> 1 file changed, 5 insertions(+), 4 deletions(-) >>> >>> diff --git a/arch/arm/boot/dts/ti/omap/omap4.dtsi b/arch/arm/boot/dts/ti/omap/omap4.dtsi >>> index 2bbff9032be3e..559b2bfe4ca7c 100644 >>> --- a/arch/arm/boot/dts/ti/omap/omap4.dtsi >>> +++ b/arch/arm/boot/dts/ti/omap/omap4.dtsi >>> @@ -501,10 +501,11 @@ sgx_module: target-module@56000000 { >>> #size-cells = <1>; >>> ranges = <0 0x56000000 0x2000000>; >>> >>> - /* >>> - * Closed source PowerVR driver, no child device >>> - * binding or driver in mainline >>> - */ >>> + gpu@0 { >> >> I wonder why we don't add a "gpu:" label here. >> >> Almost all other subsystem nodes have one (e.g. emif:, aes:, dss:, dsi:, hdmi:, etc.), >> obviously for convenience when using a .dtsi file. >> >> It would allow a board-specific DTS to easily add status = "disabled" to avoid driver >> probing or disabling the GPU (e.g. if there is no display). > > There's no reason to disable it in the DT: the hardware block would > still be there and it's rendering to memory so it still could be useful. Well, if you know that the board does not have a dm3730 but a dm3725 without GPU it is better to disable the GPU completely instead of loading the driver and make it detect by some internal bits that it has no GPU on the SoC. > If there's no display on the board and you really don't want the GPU > driver, then you can disable the driver or block the module loading, but > it should be a distro / package / user decision, not a DT / kernel one > still. The same holds for aes: dss: dsi: hdmi: etc. If they are not used by some board file, they don't change a single bit of the DTB [1] which IMHO would be of reasonable concern to question additional labels. BR and thanks, Nikolaus [1] https://devicetree-specification.readthedocs.io/en/stable/source-language.html "Labels are only used in the devicetree source format and are not encoded into the DTB binary."
Hi, On Mon, 15 Jan 2024 09:55:00 +0100 "H. Nikolaus Schaller" <hns@goldelico.com> wrote: > > There's no reason to disable it in the DT: the hardware block would > > still be there and it's rendering to memory so it still could be useful. > > Well, if you know that the board does not have a dm3730 but a dm3725 without > GPU it is better to disable the GPU completely instead of loading the driver > and make it detect by some internal bits that it has no GPU on the SoC. > That is at least some valid reason. > > If there's no display on the board and you really don't want the GPU > > driver, then you can disable the driver or block the module loading, but > > it should be a distro / package / user decision, not a DT / kernel one > > still. > > The same holds for aes: dss: dsi: hdmi: etc. If they are not used by some > board file, they don't change a single bit of the DTB [1] which IMHO would > be of reasonable concern to question additional labels. There is some difference here, some hardware can just not be used without wired external pins, the gpu can be used even if no display is connected either to accelerate some remote access or you could use the gpu for something completely else... Maybe mining bitcoins if temperate gets too low to warm you pocket ;-) But as these labels do not harm, I have no strong opinion against it. Regards, Andreas
On Mon, Jan 15, 2024 at 09:55:00AM +0100, H. Nikolaus Schaller wrote: > Hi, > > > Am 15.01.2024 um 09:25 schrieb Maxime Ripard <mripard@kernel.org>: > > > > Hi, > > > > On Fri, Jan 12, 2024 at 06:33:58PM +0100, H. Nikolaus Schaller wrote: > >>> Am 08.01.2024 um 19:32 schrieb Andrew Davis <afd@ti.com>: > >>> > >>> Add SGX GPU device entry to base OMAP4 dtsi file. > >>> > >>> Signed-off-by: Andrew Davis <afd@ti.com> > >>> --- > >>> arch/arm/boot/dts/ti/omap/omap4.dtsi | 9 +++++---- > >>> 1 file changed, 5 insertions(+), 4 deletions(-) > >>> > >>> diff --git a/arch/arm/boot/dts/ti/omap/omap4.dtsi b/arch/arm/boot/dts/ti/omap/omap4.dtsi > >>> index 2bbff9032be3e..559b2bfe4ca7c 100644 > >>> --- a/arch/arm/boot/dts/ti/omap/omap4.dtsi > >>> +++ b/arch/arm/boot/dts/ti/omap/omap4.dtsi > >>> @@ -501,10 +501,11 @@ sgx_module: target-module@56000000 { > >>> #size-cells = <1>; > >>> ranges = <0 0x56000000 0x2000000>; > >>> > >>> - /* > >>> - * Closed source PowerVR driver, no child device > >>> - * binding or driver in mainline > >>> - */ > >>> + gpu@0 { > >> > >> I wonder why we don't add a "gpu:" label here. > >> > >> Almost all other subsystem nodes have one (e.g. emif:, aes:, dss:, dsi:, hdmi:, etc.), > >> obviously for convenience when using a .dtsi file. > >> > >> It would allow a board-specific DTS to easily add status = "disabled" to avoid driver > >> probing or disabling the GPU (e.g. if there is no display). > > > > There's no reason to disable it in the DT: the hardware block would > > still be there and it's rendering to memory so it still could be useful. > > Well, if you know that the board does not have a dm3730 but a dm3725 without > GPU it is better to disable the GPU completely instead of loading the driver > and make it detect by some internal bits that it has no GPU on the SoC. It shouldn't even be in the DTSI if it's not in the SoC. > > If there's no display on the board and you really don't want the GPU > > driver, then you can disable the driver or block the module loading, but > > it should be a distro / package / user decision, not a DT / kernel one > > still. > > The same holds for aes: dss: dsi: hdmi: etc. If they are not used by some > board file, they don't change a single bit of the DTB [1] which IMHO would > be of reasonable concern to question additional labels. Not really, no. If there's no HDMI connector, the HDMI controller is useless. A GPU without a display can still be useful, depending on the workload. Maxime
diff --git a/arch/arm/boot/dts/ti/omap/omap4.dtsi b/arch/arm/boot/dts/ti/omap/omap4.dtsi index 2bbff9032be3e..559b2bfe4ca7c 100644 --- a/arch/arm/boot/dts/ti/omap/omap4.dtsi +++ b/arch/arm/boot/dts/ti/omap/omap4.dtsi @@ -501,10 +501,11 @@ sgx_module: target-module@56000000 { #size-cells = <1>; ranges = <0 0x56000000 0x2000000>; - /* - * Closed source PowerVR driver, no child device - * binding or driver in mainline - */ + gpu@0 { + compatible = "ti,omap4430-gpu", "img,powervr-sgx540"; + reg = <0x0 0x2000000>; /* 32MB */ + interrupts = <GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>; + }; }; /*
Add SGX GPU device entry to base OMAP4 dtsi file. Signed-off-by: Andrew Davis <afd@ti.com> --- arch/arm/boot/dts/ti/omap/omap4.dtsi | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)