| Message ID | cover.1724159867.git.andrea.porta@suse.com |
|---|---|
| Headers | show |
| Series | Add support for RaspberryPi RP1 PCI device using a DT overlay | expand |
Hi Andrew, On 15:04 Thu 22 Aug , Andrew Lunn wrote: > > WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP > > #673: FILE: drivers/pinctrl/pinctrl-rp1.c:600: > > + return -ENOTSUPP; > > > > This I must investigate: I've already tried to fix it before sending the patchset > > but for some reason it wouldn't work, so I planned to fix it in the upcoming > > releases. > > ENOTSUPP is an NFS error. It should not be used outside for NFS. You > want EOPNOTSUPP. Ack. > > > > WARNING: externs should be avoided in .c files > > #331: FILE: drivers/misc/rp1/rp1-pci.c:58: > > +extern char __dtbo_rp1_pci_begin[]; > > > > True, but in this case we don't have a symbol that should be exported to other > > translation units, it just needs to be referenced inside the driver and > > consumed locally. Hence it would be better to place the extern in .c file. > > Did you try making it static. The dtso is compiled into an obj and linked with the driver which is in a different transaltion unit. I'm not aware on other ways to include that symbol without declaring it extern (the exception being some hackery trick that compile the dtso into a .c file to be included into the driver main source file). Or probably I'm not seeing what you are proposing, could you please elaborate on that? Many thanks, Andrea > > Andrew
> > > WARNING: externs should be avoided in .c files > > > #331: FILE: drivers/misc/rp1/rp1-pci.c:58: > > > +extern char __dtbo_rp1_pci_begin[]; > > > > > > True, but in this case we don't have a symbol that should be exported to other > > > translation units, it just needs to be referenced inside the driver and > > > consumed locally. Hence it would be better to place the extern in .c file. > > > > Did you try making it static. > > The dtso is compiled into an obj and linked with the driver which is in > a different transaltion unit. I'm not aware on other ways to include that > symbol without declaring it extern (the exception being some hackery > trick that compile the dtso into a .c file to be included into the driver > main source file). > Or probably I'm not seeing what you are proposing, could you please elaborate > on that? Sorry, i jumped to the wrong conclusion. Often it is missing static keyword which causes warnings. However, you say it needs to be global scope. Reading the warning again: > > > WARNING: externs should be avoided in .c files It is wanting you to put it in a .h file, which then gets included by the two users. Andrew
Hi Krzysztof, On 11:50 Thu 22 Aug , Krzysztof Kozlowski wrote: > On 22/08/2024 11:05, Andrea della Porta wrote: > > Hi Krzysztof, > > > > On 15:42 Wed 21 Aug , Krzysztof Kozlowski wrote: > >> On 20/08/2024 16:36, Andrea della Porta wrote: > >>> RP1 is an MFD chipset that acts as a south-bridge PCIe endpoint sporting > >>> a pletora of subdevices (i.e. Ethernet, USB host controller, I2C, PWM, > >>> etc.) whose registers are all reachable starting from an offset from the > >>> BAR address. The main point here is that while the RP1 as an endpoint > >>> itself is discoverable via usual PCI enumeraiton, the devices it contains > >>> are not discoverable and must be declared e.g. via the devicetree. > >>> > >>> This patchset is an attempt to provide a minimum infrastructure to allow > >>> the RP1 chipset to be discovered and perpherals it contains to be added > >>> from a devictree overlay loaded during RP1 PCI endpoint enumeration. > >>> Followup patches should add support for the several peripherals contained > >>> in RP1. > >>> > >>> This work is based upon dowstream drivers code and the proposal from RH > >>> et al. (see [1] and [2]). A similar approach is also pursued in [3]. > >> > >> Looking briefly at findings it seems this was not really tested by > >> automation and you expect reviewers to find issues which are pointed out > >> by tools. That's not nice approach. Reviewer's time is limited, while > >> tools do it for free. And the tools are free - you can use them without > >> any effort. > > > > Sorry if I gave you that impression, but this is not obviously the case. > > Just look at number of reports... so many sparse reports that I wonder > how it is not the case. > > And many kbuild reports. Ack. > > > I've spent quite a bit of time in trying to deliver a patchset that ease > > your and others work, at least to the best I can. In fact, I've used many > > of the checking facilities you mentioned before sending it, solving all > > of the reported issues, except the ones for which there are strong reasons > > to leave untouched, as explained below. > > > >> > >> It does not look like you tested the DTS against bindings. Please run > >> `make dtbs_check W=1` (see > >> Documentation/devicetree/bindings/writing-schema.rst or > >> https://www.linaro.org/blog/tips-and-tricks-for-validating-devicetree-sources-with-the-devicetree-schema/ > >> for instructions). > > > > #> make W=1 dt_binding_check DT_SCHEMA_FILES=raspberrypi,rp1-gpio.yaml > > CHKDT Documentation/devicetree/bindings > > LINT Documentation/devicetree/bindings > > DTEX Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.example.dts > > DTC_CHK Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.example.dtb > > > > #> make W=1 dt_binding_check DT_SCHEMA_FILES=raspberrypi,rp1-clocks.yaml > > CHKDT Documentation/devicetree/bindings > > LINT Documentation/devicetree/bindings > > DTEX Documentation/devicetree/bindings/clock/raspberrypi,rp1-clocks.example.dts > > DTC_CHK Documentation/devicetree/bindings/clock/raspberrypi,rp1-clocks.example.dtb > > > > I see no issues here, in case you've found something different, I kindly ask you to post > > the results. > > > > #> make W=1 CHECK_DTBS=y broadcom/rp1.dtbo > > DTC arch/arm64/boot/dts/broadcom/rp1.dtbo > > arch/arm64/boot/dts/broadcom/rp1.dtso:37.24-42.7: Warning (simple_bus_reg): /fragment@0/__overlay__/rp1@0/clk_xosc: missing or empty reg/ranges property > > arch/arm64/boot/dts/broadcom/rp1.dtso:44.26-49.7: Warning (simple_bus_reg): /fragment@0/__overlay__/rp1@0/macb_pclk: missing or empty reg/ranges property > > arch/arm64/boot/dts/broadcom/rp1.dtso:51.26-56.7: Warning (simple_bus_reg): /fragment@0/__overlay__/rp1@0/macb_hclk: missing or empty reg/ranges property > > arch/arm64/boot/dts/broadcom/rp1.dtso:14.15-173.5: Warning (avoid_unnecessary_addr_size): /fragment@0/__overlay__: unnecessary #address-cells/#size-cells without "ranges", "dma-ranges" or child "reg" property > > > > I believe that These warnings are unavoidable, and stem from the fact that this > > is quite a peculiar setup (PCI endpoint which dynamically loads platform driver > > addressable via BAR). > > The missing reg/ranges in the threee clocks are due to the simple-bus of the > > containing node to which I believe they should belong: I did a test to place > > This is not the place where they belong. non-MMIO nodes should not be > under simple-bus. Ack. > > > those clocks in the same dtso under root or /clocks node but AFAIK it doesn't > > seems to work. I could move them in a separate dtso to be loaded before the main > > Well... who instantiates them? If they are in top-level, then > CLK_OF_DECLARE which is not called at your point? > > You must instantiate clocks different way, since they are not part of > "rp1". That's another bogus DT description... external oscilator is not > part of RP1. > Ok, I'll dive into that and see what I can come up with. Many thanks for this feedback. > > > one but this is IMHO even more cumbersome than having a couple of warnings in > > CHECK_DTBS. > > Of course, if you have any suggestion on how to improve it I would be glad to > > discuss. > > About the last warning about the address/size-cells, if I drop those two lines > > in the _overlay_ node it generates even more warning, so again it's a "don't fix" > > one. > > > >> > >> Please run standard kernel tools for static analysis, like coccinelle, > >> smatch and sparse, and fix reported warnings. Also please check for > >> warnings when building with W=1. Most of these commands (checks or W=1 > >> build) can build specific targets, like some directory, to narrow the > >> scope to only your code. The code here looks like it needs a fix. Feel > >> free to get in touch if the warning is not clear. > > > > I didn't run those static analyzers since I've preferred a more "manual" aproach > > by carfeully checking the code, but I agree that something can escape even the > > more carefully executed code inspection so I will add them to my arsenal from > > now on. Thanks for the heads up. > > I don't care if you do not run static analyzers if you produce good > code. But if you produce bugs which could have been easily spotted with > sparser, than it is different thing. > > Start running static checkers instead of asking reviewers to do that. Ack. > > > > >> > >> Please run scripts/checkpatch.pl and fix reported warnings. Then please > >> run `scripts/checkpatch.pl --strict` and (probably) fix more warnings. > >> Some warnings can be ignored, especially from --strict run, but the code > >> here looks like it needs a fix. Feel free to get in touch if the warning > >> is not clear. > >> > > > > Again, most of checkpatch's complaints have been addressed, the remaining > > ones I deemed as not worth fixing, for example:> > > #> scripts/checkpatch.pl --strict --codespell tmp/*.patch > > > > WARNING: please write a help paragraph that fully describes the config symbol > > #42: FILE: drivers/clk/Kconfig:91: > > +config COMMON_CLK_RP1 > > + tristate "Raspberry Pi RP1-based clock support" > > + depends on PCI || COMPILE_TEST > > + depends on COMMON_CLK > > + help > > + Enable common clock framework support for Raspberry Pi RP1. > > + This mutli-function device has 3 main PLLs and several clock > > + generators to drive the internal sub-peripherals. > > + > > > > I don't understand this warning, the paragraph is there and is more or less similar > > to many in the same file that are already upstream. Checkpatch bug? > > > > > > CHECK: Alignment should match open parenthesis > > #1541: FILE: drivers/clk/clk-rp1.c:1470: > > + if (WARN_ON_ONCE(clock_data->num_std_parents > AUX_SEL && > > + strcmp("-", clock_data->parents[AUX_SEL]))) > > > > This would have worsen the code readability. > > > > > > WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP > > #673: FILE: drivers/pinctrl/pinctrl-rp1.c:600: > > + return -ENOTSUPP; > > > > This I must investigate: I've already tried to fix it before sending the patchset > > but for some reason it wouldn't work, so I planned to fix it in the upcoming > > releases. > > > > > > WARNING: externs should be avoided in .c files > > #331: FILE: drivers/misc/rp1/rp1-pci.c:58: > > +extern char __dtbo_rp1_pci_begin[]; > > > > True, but in this case we don't have a symbol that should be exported to other > > translation units, it just needs to be referenced inside the driver and > > consumed locally. Hence it would be better to place the extern in .c file. > > > > > > Apologies for a couple of other warnings that I could have seen in the first > > place, but honestly they don't seems to be a big deal (one typo and on over > > 100 chars comment, that will be fixed in next patch version). > > Again, judging by number of reports from checkers that is a big deal, > because it is your task to run the tools. Ack. Many thanks, Andrea > > Best regards, > Krzysztof >
Hi Andrew, On 15:04 Thu 29 Aug , Andrew Lunn wrote: > > > > WARNING: externs should be avoided in .c files > > > > #331: FILE: drivers/misc/rp1/rp1-pci.c:58: > > > > +extern char __dtbo_rp1_pci_begin[]; > > > > > > > > True, but in this case we don't have a symbol that should be exported to other > > > > translation units, it just needs to be referenced inside the driver and > > > > consumed locally. Hence it would be better to place the extern in .c file. > > > > > > Did you try making it static. > > > > The dtso is compiled into an obj and linked with the driver which is in > > a different transaltion unit. I'm not aware on other ways to include that > > symbol without declaring it extern (the exception being some hackery > > trick that compile the dtso into a .c file to be included into the driver > > main source file). > > Or probably I'm not seeing what you are proposing, could you please elaborate > > on that? > > Sorry, i jumped to the wrong conclusion. Often it is missing static > keyword which causes warnings. However, you say it needs to be global > scope. > > Reading the warning again: > > > > > WARNING: externs should be avoided in .c files > > It is wanting you to put it in a .h file, which then gets > included by the two users. Ah I see now what you were referring to, thanks. I'll put the extern into an header file, although there are no two users of that, the only one being rp1-pci.c. Many thanks, Andrea > > Andrew
Hi Andrew, On 15:04 Thu 29 Aug , Andrew Lunn wrote: > > > > WARNING: externs should be avoided in .c files > > > > #331: FILE: drivers/misc/rp1/rp1-pci.c:58: > > > > +extern char __dtbo_rp1_pci_begin[]; > > > > > > > > True, but in this case we don't have a symbol that should be exported to other > > > > translation units, it just needs to be referenced inside the driver and > > > > consumed locally. Hence it would be better to place the extern in .c file. > > > > > > Did you try making it static. > > > > The dtso is compiled into an obj and linked with the driver which is in > > a different transaltion unit. I'm not aware on other ways to include that > > symbol without declaring it extern (the exception being some hackery > > trick that compile the dtso into a .c file to be included into the driver > > main source file). > > Or probably I'm not seeing what you are proposing, could you please elaborate > > on that? > > Sorry, i jumped to the wrong conclusion. Often it is missing static > keyword which causes warnings. However, you say it needs to be global > scope. > > Reading the warning again: > > > > > WARNING: externs should be avoided in .c files > > It is wanting you to put it in a .h file, which then gets > included by the two users. On a second thought, are you really sure we want to proceed with the header file? After all the only line in it would be the extern declaration and the only one to include it would be rp1-dev.c. Moreover, an header file would convey the false premise that you can include it and use that symbol while in fact it should be only used inside the driver. OTOH, not creating that header file will continue to trigger the warning... Many thanks, Andrea > > Andrew
> On a second thought, are you really sure we want to proceed with the header file? > After all the only line in it would be the extern declaration and the only one to > include it would be rp1-dev.c. Moreover, an header file would convey the false > premise that you can include it and use that symbol while in fact it should be > only used inside the driver. > OTOH, not creating that header file will continue to trigger the warning... The header file does not need to be in global scope. It could be in the driver source directory. As such, nothing outside of the driver can use it. Headers like this have multiple proposes. One is they make a symbol visible to the linker. But having two different .c files include the header enables type checking, which for long term maintenance is just as important. So a one line header is fine. Andrew
Hi Andrew, On 16:10 Fri 30 Aug , Andrew Lunn wrote: > > On a second thought, are you really sure we want to proceed with the header file? > > After all the only line in it would be the extern declaration and the only one to > > include it would be rp1-dev.c. Moreover, an header file would convey the false > > premise that you can include it and use that symbol while in fact it should be > > only used inside the driver. > > OTOH, not creating that header file will continue to trigger the warning... > > The header file does not need to be in global scope. It could be in > the driver source directory. As such, nothing outside of the driver > can use it. Ack. > > Headers like this have multiple proposes. One is they make a symbol > visible to the linker. But having two different .c files include the Hmm... not sure what second file is including it, since only rp1_pci.c needs it. > header enables type checking, which for long term maintenance is just > as important. So a one line header is fine. Done. Cheers, Andrea > > Andrew >