[PATCH] drm: hibmc: Use set_busid function from drm core

[Daniel Vetter]

On Tue, Jun 13, 2017 at 10:23:34AM +0100, Emil Velikov wrote:
> Hi Daniel,
> 
> On 9 June 2017 at 07:57, Daniel Axtens <dja at axtens.net> wrote:
> > Currently, calling drmGetBusid from libdrm on a hibmc VGA
> > card returns a string like "0007:a1:00.0".
> >
> > The busid reported by most cards begins with "pci:". For
> > example, on an amd64 system, a VGA card reported
> > "pci:0000:00:02.0".
> >
> > The missing "pci:" prefix confuses Xorg and leads to crashes
> > and other misbehaviour.[0]
> >
> > Use the standard helper from the drm core to set the busid to
> > include the "pci:" prefix. This is done by many other drivers.
> >
> > With this patch, Xorg can be run successfully.
> >
> > [0]: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1691991
> >
> > Cc: Xinliang Liu <z.liuxinliang at hisilicon.com>
> > Cc: Rongrong Zou <zourongrong at gmail.com>
> > Signed-off-by: Daniel Axtens <dja at axtens.net>
> > ---
> >  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > index 2ffdbf9801bd..9663a633897a 100644
> > --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > @@ -69,6 +69,7 @@ static struct drm_driver hibmc_driver = {
> >         .dumb_map_offset        = hibmc_dumb_mmap_offset,
> >         .dumb_destroy           = drm_gem_dumb_destroy,
> >         .irq_handler            = hibmc_drm_interrupt,
> > +       .set_busid              = drm_pci_set_busid,
> 
> Daniel V has been working very hard on cleaning all the set_busid
> "chaos" and even has some patches which remove it completely [1].
> While your patch is correct, it would be nicer if we can remove the
> code so that nobody else gets bitten ;-)

Yeah I just applied my patches to nuke the set_busid callback. Pls drop
this one. If you want this backported, I guess we could cherry-pick it
over with a cc: stable (it's likely only going to reach 4.14 as-is).
-Daniel

> 
> Can you be so kind and re-spin your patch with the cleanups (2-4) on top?
> IIRC your fix should be CC kernel-stable.
> 
> Thanks
> Emil
> 
> [1] https://lists.freedesktop.org/archives/dri-devel/2017-May/142670.html

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch