Re: [PATCH] video/aperture: match the pci device when calling sysfb_disable()

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Am 19.08.24 um 10:04 schrieb Thomas Zimmermann:
> Hi
>
> Am 16.08.24 um 22:57 schrieb Alex Deucher:
> > On Mon, Aug 12, 2024 at 8:10 AM Thomas Zimmermann 
> > <tzimmermann@xxxxxxx> wrote:
> > > Hi
> > >
> > > Am 10.08.24 um 13:44 schrieb kernel test robot:
> > > > Hi Alex,
> > > >
> > > > kernel test robot noticed the following build errors:
> > > >
> > > > [auto build test ERROR on drm-misc/drm-misc-next]
> > > > [also build test ERROR on linus/master v6.11-rc2 next-20240809]
> > > > [If your patch is applied to the wrong git tree, kindly drop us a 
> > > > note.
> > > > And when submitting patch, we suggest to use '--base' as documented in
> > > > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > > >
> > > > url: 
> > > > https://github.com/intel-lab-lkp/linux/commits/Alex-Deucher/video-aperture-match-the-pci-device-when-calling-sysfb_disable/20240810-021357
> > > > base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
> > > > patch link: 
> > > > https://lore.kernel.org/r/20240809150327.2485848-1-alexander.deucher%40amd.com
> > > > patch subject: [PATCH] video/aperture: match the pci device when 
> > > > calling sysfb_disable()
> > > > config: csky-randconfig-001-20240810 
> > > > (https://download.01.org/0day-ci/archive/20240810/202408101951.tXyqYOzv-lkp@xxxxxxxxx/config)
> > > > compiler: csky-linux-gcc (GCC) 14.1.0
> > > > reproduce (this is a W=1 build): 
> > > > (https://download.01.org/0day-ci/archive/20240810/202408101951.tXyqYOzv-lkp@xxxxxxxxx/reproduce)
> > > >
> > > > If you fix the issue in a separate patch/commit (i.e. not just a 
> > > > new version of
> > > > the same patch/commit), kindly add following tags
> > > > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > > | Closes: 
> > > > https://lore.kernel.org/oe-kbuild-all/202408101951.tXyqYOzv-lkp@xxxxxxxxx/
> > > >
> > > > All errors (new ones prefixed by >>):
> > > >
> > > >      csky-linux-ld: drivers/video/aperture.o: in function 
> > > > `aperture_remove_conflicting_pci_devices':
> > > > > > aperture.c:(.text+0x222): undefined reference to 
> > > > > > `screen_info_pci_dev'
> > > Strange. There's a already placeholder [1] for architectures without
> > > PCI. Otherwise the source file is listed at [2].
> > So I dug into this, and the problem seems to be that
> > CONFIG_SCREEN_INFO is not defined in that config.  I can't figure out
> > how this should work in that case or why this is not a problem in
> > drivers/firmware/sysfb.c.
> >
> > Something like this works:
> > diff --git a/drivers/video/aperture.c b/drivers/video/aperture.c
> > index 56a5a0bc2b1af..50e98210c9fe5 100644
> > --- a/drivers/video/aperture.c
> > +++ b/drivers/video/aperture.c
> > @@ -347,7 +347,9 @@ EXPORT_SYMBOL(__aperture_remove_legacy_vga_devices);
> >    */
> >   int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev,
> > const char *name)
> >   {
> > +#if defined(CONFIG_SCREEN_INFO)
> >          struct screen_info *si = &screen_info;
> > +#endif
> >          bool primary = false;
> >          resource_size_t base, size;
> >          int bar, ret = 0;
> > @@ -355,8 +357,10 @@ int
> > aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const
> > char *na
> >          if (pdev == vga_default_device())
> >                  primary = true;
> >
> > +#if defined(CONFIG_SCREEN_INFO)
> >          if (pdev == screen_info_pci_dev(si))
> >                  sysfb_disable();
> > +#endif
> >
> >          for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) {
> >                  if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM))
> >
> > But that can't be the right fix...  Any ideas?
>
> Thanks for investigating. I'd say we should pass the device 
> (pdev->dev) to sysfb_disable() and  do the test there. In sysfb.c, 
> next to sysfb_disable(), you'll find sysfb_parent_dev(), which gives 
> the Linux device of the screen_info.
>
> The code then looks something like this:
>
> sysfb_disable(struct device *dev)
> {
>     if (dev && dev == sysfb_parent_dev(screen_info))

s/==/!=

> return
>
>   /* else do the current code */
> }
>
> there's an invocation of sysfb_disable() in drivers/of/platform.c 
> where you can pass NULL.
>
> Best regards
> Thomas
>
> > Alex
> >
> > > [1]
> > > https://elixir.bootlin.com/linux/v6.10/source/include/linux/screen_info.h#L127 
> > >
> > > [2] 
> > > https://elixir.bootlin.com/linux/v6.10/source/drivers/video/Makefile#L11 
> > >
> > >
> > > Best regards
> > > Thomas
> > >
> > > >      csky-linux-ld: drivers/video/aperture.o: in function 
> > > > `devm_aperture_acquire_release':
> > > > > > aperture.c:(.text+0x2c0): undefined reference to `screen_info'
> > > > > > csky-linux-ld: aperture.c:(.text+0x2c4): undefined reference to 
> > > > > > `screen_info_pci_dev'
> > > --
> > > --
> > > Thomas Zimmermann
> > > Graphics Driver Developer
> > > SUSE Software Solutions Germany GmbH
> > > Frankenstrasse 146, 90461 Nuernberg, Germany
> > > GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
> > > HRB 36809 (AG Nuernberg)

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)