[Public] Reviewed-by: Guchun Chen <[email protected]>
Regards, Guchun > -----Original Message----- > From: SHANMUGAM, SRINIVASAN <[email protected]> > Sent: Wednesday, August 9, 2023 3:29 PM > To: Koenig, Christian <[email protected]>; Deucher, Alexander > <[email protected]>; Chen, Guchun <[email protected]>; > Pan, Xinhui <[email protected]> > Cc: [email protected]; SHANMUGAM, SRINIVASAN > <[email protected]> > Subject: [PATCH v4] drm/amdgpu: Fix missing comment for mb() in > 'amdgpu_device_aper_access' > > This patch adds the missing code comment for memory barrier > > WARNING: memory barrier without comment > + mb(); > > WARNING: memory barrier without comment > + mb(); > > Cc: Guchun Chen <[email protected]> > Cc: Christian König <[email protected]> > Cc: Alex Deucher <[email protected]> > Cc: "Pan, Xinhui" <[email protected]> > Signed-off-by: Srinivasan Shanmugam <[email protected]> > --- > v4: > - Incorporated comments from (Lijo) > > drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > index 4f818f13dc9d..65c36987f7d6 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -305,10 +305,16 @@ size_t amdgpu_device_aper_access(struct > amdgpu_device *adev, loff_t pos, > > if (write) { > memcpy_toio(addr, buf, count); > + /* Make sure HDP write cache flush happens without > any reordering > + * after the system memory contents are sent over > PCIe device > + */ > mb(); > amdgpu_device_flush_hdp(adev, NULL); > } else { > amdgpu_device_invalidate_hdp(adev, NULL); > + /* Make sure HDP read cache is invalidated before > issuing a read > + * to the PCIe device > + */ > mb(); > memcpy_fromio(buf, addr, count); > } > -- > 2.25.1
