[Freedreno] [RFC PULL] Add Display Support for Qualcomm SDM845

[Rob Clark]

On Tue, Feb 13, 2018 at 7:02 PM, Jordan Crouse <jcrouse at codeaurora.org> wrote:
> On Tue, Feb 13, 2018 at 02:18:13PM -0500, Sean Paul wrote:
>> Hi dri-devel,
>> Qualcomm has been working for the past few weeks on forward porting their
>> downstream drm driver from 4.14 to mainline. Please consider this PR as a
>> request for review, rather than an attempt at mainlining the code as it
>> currently stands. The goal is get this driver in shape over the next coming
>> months.
>>
>> In the meantime, I'll be hosting a tree here [1] to stage the fixes. Patches
>> will be posted and reviewed on linux-arm-msm at vger.kernel.org. Once things look
>> good, I'll send another pull 4realz.
>>
>>  drivers/gpu/drm/msm/msm_rd.c                       |   58 +-
>
> These changes are somewhat overzealous pointer verification, If
> struct file * and/or struct inode * are NULL in a fops function your system is
> already having a bad day. The only check that might be somewhat reasonable is
> for gpu->funcs->get_param but that hook is defined on all targets so I don't
> think it is unreasonable to assume that it should be there (and if it isn't the
> unit test sure better catch it). We can safely drop these changes.
>

thanks, this was something I didn't notice (or test) yet.. a couple of
the other 'elfring fixes' I encountered (I guess there are probably
some coding standards or static analysis behind this?) actually broke
things and I have already reverted in the course of unbreaking
display/gpu on db410c..

But yeah, ->get_param() is mandatory in the ioctl path (which is
something you don't need debugfs access for).. for the paranoid
probably the better thing would be a WARN_ON(!gpu->get_param) in gpu
init path.

BR,
-R