On 04.12.2023 12:42, AngeloGioacchino Del Regno wrote:
> Some SoCs may be equipped with a GPU containing two core groups
> and this is exactly the case of Samsung's Exynos 5422 featuring
> an ARM Mali-T628 MP6 GPU: the support for this GPU in Panfrost
> is partial, as this driver currently supports using only one
> core group and that's reflected on all parts of it, including
> the power on (and power off, previously to this patch) function.
>
> The issue with this is that even though executing the soft reset
> operation should power off all cores unconditionally, on at least
> one platform we're seeing a crash that seems to be happening due
> to an interrupt firing which may be because we are calling power
> transition only on the first core group, leaving the second one
> unchanged, or because ISR execution was pending before entering
> the panfrost_gpu_power_off() function and executed after powering
> off the GPU cores, or all of the above.
>
> Finally, solve this by:
> - Avoid to enable the power transition interrupt on reset; and
> - Ignoring the core_mask and ask the GPU to poweroff both core groups
>
> Fixes: 22aa1a209018 ("drm/panfrost: Really power off GPU cores in panfrost_gpu_power_off()")
> Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Reviewed-by: Steven Price <steven.price@xxxxxxx>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/panfrost/panfrost_gpu.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> ...
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
