Unverified Commit 74ef7844 authored by Alessio Belle's avatar Alessio Belle Committed by Matt Coster
Browse files

drm/imagination: Disable interrupts before suspending the GPU 



This is an additional safety layer to ensure no accesses to the GPU
registers can be made while it is powered off.

While we can disable IRQ generation from GPU, META firmware, MIPS
firmware and for safety events, we cannot do the same for the RISC-V
firmware.
To keep a unified approach, once the firmware has completed its power
off sequence, disable IRQs for the while GPU at the kernel level
instead.

Signed-off-by: default avatarAlessio Belle <alessio.belle@imgtec.com>
Reviewed-by: default avatarMatt Coster <matt.coster@imgtec.com>
Link: https://patch.msgid.link/20260310-drain-irqs-before-suspend-v1-2-bf4f9ed68e75@imgtec.com


Signed-off-by: default avatarMatt Coster <matt.coster@imgtec.com>
parent 2d7f05cd

drivers/gpu/drm/imagination/pvr_power.c

+23 −10
Original line number Diff line number Diff line
@@ -92,9 +92,9 @@ pvr_power_request_pwr_off(struct pvr_device *pvr_dev) 
static int

pvr_power_fw_disable(struct pvr_device *pvr_dev, bool hard_reset, bool rpm_suspend)

{

	if (!hard_reset) {

	int err;



	if (!hard_reset) {

		cancel_delayed_work_sync(&pvr_dev->watchdog.work);



		err = pvr_power_request_idle(pvr_dev);
@@ -107,33 +107,46 @@ pvr_power_fw_disable(struct pvr_device *pvr_dev, bool hard_reset, bool rpm_suspe 
	}



	if (rpm_suspend) {

		/* Wait for late processing of GPU or firmware IRQs in other cores */

		synchronize_irq(pvr_dev->irq);

		/* This also waits for late processing of GPU or firmware IRQs in other cores */

		disable_irq(pvr_dev->irq);

	}



	return pvr_fw_stop(pvr_dev);

	err = pvr_fw_stop(pvr_dev);

	if (err && rpm_suspend)

		enable_irq(pvr_dev->irq);



	return err;

}



static int

pvr_power_fw_enable(struct pvr_device *pvr_dev)

pvr_power_fw_enable(struct pvr_device *pvr_dev, bool rpm_resume)

{

	int err;



	if (rpm_resume)

		enable_irq(pvr_dev->irq);



	err = pvr_fw_start(pvr_dev);

	if (err)

		return err;

		goto out;



	err = pvr_wait_for_fw_boot(pvr_dev);

	if (err) {

		drm_err(from_pvr_device(pvr_dev), "Firmware failed to boot\n");

		pvr_fw_stop(pvr_dev);

		return err;

		goto out;

	}



	queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,

			   msecs_to_jiffies(WATCHDOG_TIME_MS));



	return 0;



out:

	if (rpm_resume)

		disable_irq(pvr_dev->irq);



	return err;

}



bool
@@ -396,7 +409,7 @@ pvr_power_device_resume(struct device *dev) 
		goto err_drm_dev_exit;



	if (pvr_dev->fw_dev.booted) {

		err = pvr_power_fw_enable(pvr_dev);

		err = pvr_power_fw_enable(pvr_dev, true);

		if (err)

			goto err_power_off;

	}
@@ -555,7 +568,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset) 


			pvr_fw_irq_clear(pvr_dev);



			err = pvr_power_fw_enable(pvr_dev);

			err = pvr_power_fw_enable(pvr_dev, false);

		}



		if (err && hard_reset)