Re: [PATCH v5 13/21] drm/imagination: Add reset controller support for GPU initialization

Michal Wilczynski
2025-04-16T14:25:08Z

On 2/19/25 15:02, Michal Wilczynski wrote:
> All IMG Rogue GPUs include a reset line that participates in the
> power-up sequence. On some SoCs (e.g., T-Head TH1520 and Banana Pi
> BPI-F3), this reset line is exposed and must be driven explicitly to
> ensure proper initialization. On others, such as the currently
> supported TI SoC, the reset logic is handled in hardware or firmware
> without exposing the line directly. In platforms where the reset line is
> externally accessible, if it is not driven correctly, the GPU may remain
> in an undefined state, leading to instability or performance issues.
>
> This commit adds a dedicated reset controller to the drm/imagination
> driver. By managing the reset line (where applicable) as part of normal
> GPU bring-up, the driver ensures reliable initialization across
> platforms regardless of whether the reset is controlled externally or
> handled internally.
>
> Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
> ---
> drivers/gpu/drm/imagination/pvr_device.c | 21 +++++++++++++++++++++
> drivers/gpu/drm/imagination/pvr_device.h | 9 +++++++++
> drivers/gpu/drm/imagination/pvr_power.c | 22 +++++++++++++++++++++-
> 3 files changed, 51 insertions(+), 1 deletion(-)
>

Hi Matt,

This commit, along with the corresponding change in the DT bindings,
doesn’t appear to conflict with the work you're doing for Rogue series
enablement.

Would you prefer if I re-send them as a mini-series so you can consider
picking them up for the next kernel release?

Regards,
Michał