[PATCH] drm/imagination: Clear runtime PM errors while resetting the GPU

[PATCH] drm/imagination: Clear runtime PM errors while resetting the GPU

[Alessio Belle]

The runtime PM might be left in error state if one of the callbacks
returned an error, e.g. if the (auto)suspend callback failed following
a firmware crash.

When that happens, any further attempt to acquire or release a power
reference will then also fail, making it impossible to do anything else
with the GPU. The driver logic will eventually reach the reset code.

In pvr_power_reset(), replace pvr_power_get() with a new API
pvr_power_get_clear() which also attempts to clear any runtime PM error
state if acquiring a power reference is not possible.

Signed-off-by: Alessio Belle <alessio.belle@imgtec.com>
---
 drivers/gpu/drm/imagination/pvr_power.c | 59 ++++++++++++++++++++++++++++++++-
 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
index 41f5d89e78b854cf6993838868a4416a220b490a..65642ded051db83e82e32e3c3e9f82508ad8d4cc 100644
--- a/drivers/gpu/drm/imagination/pvr_power.c
+++ b/drivers/gpu/drm/imagination/pvr_power.c
@@ -340,6 +340,63 @@ pvr_power_device_idle(struct device *dev)
 	return pvr_power_is_idle(pvr_dev) ? 0 : -EBUSY;
 }
 
+static int
+pvr_power_clear_error(struct pvr_device *pvr_dev)
+{
+	struct device *dev = from_pvr_device(pvr_dev)->dev;
+	int err;
+
+	/* Ensure the device state is known and nothing is happening past this point */
+	pm_runtime_disable(dev);
+
+	/* Attempt to clear the runtime PM error by setting the current state again */
+	if (pm_runtime_status_suspended(dev))
+		err = pm_runtime_set_suspended(dev);
+	else
+		err = pm_runtime_set_active(dev);
+
+	if (err) {
+		drm_err(from_pvr_device(pvr_dev),
+			"%s: Failed to clear runtime PM error (new error %d)\n",
+			__func__, err);
+	}
+
+	pm_runtime_enable(dev);
+
+	return err;
+}
+
+/**
+ * pvr_power_get_clear() - Acquire a power reference, correcting any errors
+ * @pvr_dev: Device pointer
+ *
+ * Attempt to acquire a power reference on the device. If the runtime PM
+ * is in error state, attempt to clear the error and retry.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * Any error code returned by pvr_power_get() or the runtime PM API.
+ */
+static int
+pvr_power_get_clear(struct pvr_device *pvr_dev)
+{
+	int err;
+
+	err = pvr_power_get(pvr_dev);
+	if (err == 0)
+		return err;
+
+	drm_warn(from_pvr_device(pvr_dev),
+		 "%s: pvr_power_get returned error %d, attempting recovery\n",
+		 __func__, err);
+
+	err = pvr_power_clear_error(pvr_dev);
+	if (err)
+		return err;
+
+	return pvr_power_get(pvr_dev);
+}
+
 /**
  * pvr_power_reset() - Reset the GPU
  * @pvr_dev: Device pointer
@@ -364,7 +421,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
 	 * Take a power reference during the reset. This should prevent any interference with the
 	 * power state during reset.
 	 */
-	WARN_ON(pvr_power_get(pvr_dev));
+	WARN_ON(pvr_power_get_clear(pvr_dev));
 
 	down_write(&pvr_dev->reset_sem);
 

---
base-commit: 1a45ef022f0364186d4fb2f4e5255dcae1ff638a
change-id: 20250619-clear-rpm-errors-gpu-reset-359ecbc85689

Best regards,
-- 
Alessio Belle <alessio.belle@imgtec.com>

Re: [PATCH] drm/imagination: Clear runtime PM errors while resetting the GPU

[Matt Coster]

[-- Attachment #1.1: Type: text/plain, Size: 3928 bytes --]

On 24/06/2025 16:01, Alessio Belle wrote:
> The runtime PM might be left in error state if one of the callbacks
> returned an error, e.g. if the (auto)suspend callback failed following
> a firmware crash.
> 
> When that happens, any further attempt to acquire or release a power
> reference will then also fail, making it impossible to do anything else
> with the GPU. The driver logic will eventually reach the reset code.
> 
> In pvr_power_reset(), replace pvr_power_get() with a new API
> pvr_power_get_clear() which also attempts to clear any runtime PM error
> state if acquiring a power reference is not possible.
> 
> Signed-off-by: Alessio Belle <alessio.belle@imgtec.com>

Reviewed-by: Matt Coster <matt.coster@imgtec.com>

I'll apply this to drm-misc-next on Friday if nobody has any objections.

Cheers,
Matt

> ---
>  drivers/gpu/drm/imagination/pvr_power.c | 59 ++++++++++++++++++++++++++++++++-
>  1 file changed, 58 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
> index 41f5d89e78b854cf6993838868a4416a220b490a..65642ded051db83e82e32e3c3e9f82508ad8d4cc 100644
> --- a/drivers/gpu/drm/imagination/pvr_power.c
> +++ b/drivers/gpu/drm/imagination/pvr_power.c
> @@ -340,6 +340,63 @@ pvr_power_device_idle(struct device *dev)
>         return pvr_power_is_idle(pvr_dev) ? 0 : -EBUSY;
>  }
> 
> +static int
> +pvr_power_clear_error(struct pvr_device *pvr_dev)
> +{
> +       struct device *dev = from_pvr_device(pvr_dev)->dev;
> +       int err;
> +
> +       /* Ensure the device state is known and nothing is happening past this point */
> +       pm_runtime_disable(dev);
> +
> +       /* Attempt to clear the runtime PM error by setting the current state again */
> +       if (pm_runtime_status_suspended(dev))
> +               err = pm_runtime_set_suspended(dev);
> +       else
> +               err = pm_runtime_set_active(dev);
> +
> +       if (err) {
> +               drm_err(from_pvr_device(pvr_dev),
> +                       "%s: Failed to clear runtime PM error (new error %d)\n",
> +                       __func__, err);
> +       }
> +
> +       pm_runtime_enable(dev);
> +
> +       return err;
> +}
> +
> +/**
> + * pvr_power_get_clear() - Acquire a power reference, correcting any errors
> + * @pvr_dev: Device pointer
> + *
> + * Attempt to acquire a power reference on the device. If the runtime PM
> + * is in error state, attempt to clear the error and retry.
> + *
> + * Returns:
> + *  * 0 on success, or
> + *  * Any error code returned by pvr_power_get() or the runtime PM API.
> + */
> +static int
> +pvr_power_get_clear(struct pvr_device *pvr_dev)
> +{
> +       int err;
> +
> +       err = pvr_power_get(pvr_dev);
> +       if (err == 0)
> +               return err;
> +
> +       drm_warn(from_pvr_device(pvr_dev),
> +                "%s: pvr_power_get returned error %d, attempting recovery\n",
> +                __func__, err);
> +
> +       err = pvr_power_clear_error(pvr_dev);
> +       if (err)
> +               return err;
> +
> +       return pvr_power_get(pvr_dev);
> +}
> +
>  /**
>   * pvr_power_reset() - Reset the GPU
>   * @pvr_dev: Device pointer
> @@ -364,7 +421,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
>          * Take a power reference during the reset. This should prevent any interference with the
>          * power state during reset.
>          */
> -       WARN_ON(pvr_power_get(pvr_dev));
> +       WARN_ON(pvr_power_get_clear(pvr_dev));
> 
>         down_write(&pvr_dev->reset_sem);
> 
> 
> ---
> base-commit: 1a45ef022f0364186d4fb2f4e5255dcae1ff638a
> change-id: 20250619-clear-rpm-errors-gpu-reset-359ecbc85689
> 
> Best regards,
> --
> Alessio Belle <alessio.belle@imgtec.com>
> 


-- 
Matt Coster
E: matt.coster@imgtec.com

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Re: [PATCH] drm/imagination: Clear runtime PM errors while resetting the GPU

[Matt Coster]

On Tue, 24 Jun 2025 16:01:31 +0100, Alessio Belle wrote:
> The runtime PM might be left in error state if one of the callbacks
> returned an error, e.g. if the (auto)suspend callback failed following
> a firmware crash.
> 
> When that happens, any further attempt to acquire or release a power
> reference will then also fail, making it impossible to do anything else
> with the GPU. The driver logic will eventually reach the reset code.
> 
> [...]

Applied, thanks!

[1/1] drm/imagination: Clear runtime PM errors while resetting the GPU
      commit: 551507e0d0bf32ce1d7d27533c4b98307380804c

Best regards,
-- 
Matt Coster <matt.coster@imgtec.com>