diff mbox series

[v2] drm/panthor: Simplify FW fast reset path

Message ID 20241119135030.3352939-1-karunika.choo@arm.com (mailing list archive)
State New
Headers show
Series [v2] drm/panthor: Simplify FW fast reset path | expand

Commit Message

Karunika Choo Nov. 19, 2024, 1:50 p.m. UTC
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@arm.com>
---
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(-)

Comments

Boris Brezillon Nov. 19, 2024, 2:25 p.m. UTC | #1
On Tue, 19 Nov 2024 13:50:29 +0000
Karunika Choo <karunika.choo@arm.com> 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@arm.com>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

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;
diff mbox series

Patch

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;