Re: [PATCH] drm/sti: Remove select of CONFIG_FW_LOADER_USER_HELPER_FALLBACK

[Takashi Iwai <tiwai@suse.de>]

On Thu, 29 Oct 2015 15:21:35 +0100,
Vincent ABRIOU wrote:
> 
> Hi Takashi,
> 
> Removing FW_LOADER_USER_HELPER_FALLBACK leads to a failure in our HQVDP 
> firmware execution.
> Indeed, our firmware is not built-in. It is a proprietary firmware 
> uploaded into the file system that's why we need the 
> USER_HELPER_FALLBACK to be able to load it once file system is available.

It's not the option a driver can set.  It's a global control option
that is applied *all* drivers.

If the fallback behavior is mandatory by a weird reason, you'd need to
adjust in a different way; e.g. modify the firmware loader code to
provide a new API for the driver to give a fallback (i.e. the another
flip of request_firmware_direct()) and use that API explicitly.

But I don't believe it's the case.  Judging from your comment, it's
your system setup that requires the user-space fallback.  So don't
make the fallback thing mandatory.


thanks,

Takashi

> 
> BR
> Vincent
> 
> On 10/19/2015 08:16 AM, Takashi Iwai wrote:
> > The commit [4fdbc678fe4d: drm: sti: add HQVDP plane] added the select
> > of CONFIG_FW_LOADER_USER_HELPER_FALLBACK by some unwritten reason.
> > But this config is known to be harmful, and is present only for
> > compatibility reason for an old exotic system that mandates udev
> > interaction which isn't supposed to be selected by a driver.
> > Let's remove it.
> >
> > Fixes: 4fdbc678fe4d ('drm: sti: add HQVDP plane')
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > ---
> >   drivers/gpu/drm/sti/Kconfig | 1 -
> >   1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/sti/Kconfig b/drivers/gpu/drm/sti/Kconfig
> > index fbccc105819b..a18159074b76 100644
> > --- a/drivers/gpu/drm/sti/Kconfig
> > +++ b/drivers/gpu/drm/sti/Kconfig
> > @@ -6,7 +6,6 @@ config DRM_STI
> >   	select DRM_GEM_CMA_HELPER
> >   	select DRM_KMS_CMA_HELPER
> >   	select DRM_PANEL
> > -	select FW_LOADER_USER_HELPER_FALLBACK
> >   	help
> >   	  Choose this option to enable DRM on STM stiH41x chipset
> >
> >