[Intel-gfx] [PATCH 3/3] drm/i915: Use rcu_dereference for rcu protected pointer

[Niranjan Vishwanathapura]

On Wed, Nov 06, 2019 at 12:36:47AM +0000, Chris Wilson wrote:
>Quoting Niranjana Vishwanathapura (2019-11-06 00:02:05)
>> 'ctx\->vm' is rcu protected, so use rcu_dereference inside
>> read side critical section. It fixes a sparse warning.
>>
>> Cc: Chris P Wilson <chris.p.wilson at intel.com>
>> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
>> ---
>>  drivers/gpu/drm/i915/gem/i915_gem_context.c | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> index de6e55af82cf..d3a622f60fd9 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> @@ -1002,12 +1002,13 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
>>         struct i915_address_space *vm;
>>         int ret;
>>
>> -       if (!rcu_access_pointer(ctx->vm))
>> -               return -ENODEV;
>
>This is correctly serialised by the caller.

Ok, is this worth fixing the sparse warning?

>-Chris