Re: [PATCH RFC 03/13] drm/msm: look for lpac from dts

[Anna Maniscalco <anna.maniscalco2000@gmail.com>]

On 7/6/26 5:04 PM, Dmitry Baryshkov wrote:
> On Sun, Jul 05, 2026 at 09:13:37PM +0200, Anna Maniscalco wrote:
>> In order to associate the SID used by LPAC to it's own domain and
>> context bank we need a separate node on the DTS.
> Can we use iommu-map instead of adding a new device using the same
> addresses? You provide zero explanations, but it seems like you are
> trying to separate a part of the GPU into a separate device, but it's
> unnecessary.

What I was trying to say is that we need to map sid0 and sid1 to 
different context banks.

 From what I recall, so long as we use the same dt node, the iommu 
drivert provides no way of doing this.

What kgsl does is having a node for the iommu and then subnodes for gfx 
lpac and secure.

The address on the lpac device doesn't really matter. I have very limted 
knowledge of DTSs but I think we could just leave it out altogether?

>
>> Add the code to look up that node on initialization.
>>
>> Signed-off-by: Anna Maniscalco <anna.maniscalco2000@gmail.com>
>> ---
>>   drivers/gpu/drm/msm/adreno/adreno_gpu.c | 21 ++++++++++++++++++++-
>>   drivers/gpu/drm/msm/msm_gpu.h           |  1 +
>>   2 files changed, 21 insertions(+), 1 deletion(-)
>>

Best regards,
-- 
Anna Maniscalco <anna.maniscalco2000@gmail.com>