On Tue, 19 Nov 2024 13:50:29 +0000
Karunika Choo <karunika.choo@xxxxxxx> wrote:
> Stop checking the FW halt_status as MCU_STATUS should be sufficient.
> This should make the check for successful FW halt and subsequently
> setting fast_reset to true more robust.
>
> We should also clear GLB_REQ.GLB_HALT bit only on post-reset prior
> to starting the FW and only if we're doing a fast reset, because
> the slow reset will re-initialize all FW sections, including the
> global interface.
>
> Signed-off-by: Karunika Choo <karunika.choo@xxxxxxx>
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
and I think you forgot to add Liviu's R-b
> ---
> v2:
> - clarify comments and commit message with regards to when to clear the
> GLB_HALT flag.
>
> drivers/gpu/drm/panthor/panthor_fw.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> index ecca5565ce41..4bc52b1b1a28 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -1098,17 +1098,11 @@ void panthor_fw_pre_reset(struct panthor_device *ptdev, bool on_hang)
> panthor_fw_update_reqs(glb_iface, req, GLB_HALT, GLB_HALT);
> gpu_write(ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1);
> if (!readl_poll_timeout(ptdev->iomem + MCU_STATUS, status,
> - status == MCU_STATUS_HALT, 10, 100000) &&
> - glb_iface->output->halt_status == PANTHOR_FW_HALT_OK) {
> + status == MCU_STATUS_HALT, 10, 100000)) {
> ptdev->fw->fast_reset = true;
> } else {
> drm_warn(&ptdev->base, "Failed to cleanly suspend MCU");
> }
> -
> - /* The FW detects 0 -> 1 transitions. Make sure we reset
> - * the HALT bit before the FW is rebooted.
> - */
> - panthor_fw_update_reqs(glb_iface, req, 0, GLB_HALT);
> }
>
> panthor_job_irq_suspend(&ptdev->fw->irq);
> @@ -1134,6 +1128,13 @@ int panthor_fw_post_reset(struct panthor_device *ptdev)
> * the FW sections. If it fails, go for a full reset.
> */
> if (ptdev->fw->fast_reset) {
> + /* The FW detects 0 -> 1 transitions. Make sure we reset
> + * the HALT bit before the FW is rebooted.
> + * This is not needed on a slow reset because FW sections are
> + * re-initialized.
> + */
> + panthor_fw_update_reqs(glb_iface, req, 0, GLB_HALT);
> +
> ret = panthor_fw_start(ptdev);
> if (!ret)
> goto out;
