[PATCH 6/9] drm/panthor: Reset GPU after L2 cache power off

[Marek Vasut]

This seems necessary on Freescale i.MX95 Mali G310 to reliably resume
from runtime PM suspend. Without this, if only the L2 is powered down
on RPM entry, the GPU gets stuck and does not indicate the firmware is
booted after RPM resume.

Signed-off-by: Marek Vasut <marex at denx.de>
---
Cc: Boris Brezillon <boris.brezillon at collabora.com>
Cc: Conor Dooley <conor+dt at kernel.org>
Cc: David Airlie <airlied at gmail.com>
Cc: Fabio Estevam <festevam at gmail.com>
Cc: Krzysztof Kozlowski <krzk+dt at kernel.org>
Cc: Liviu Dudau <liviu.dudau at arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
Cc: Philipp Zabel <p.zabel at pengutronix.de>
Cc: Rob Herring <robh at kernel.org>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Sebastian Reichel <sre at kernel.org>
Cc: Shawn Guo <shawnguo at kernel.org>
Cc: Simona Vetter <simona at ffwll.ch>
Cc: Steven Price <steven.price at arm.com>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: devicetree at vger.kernel.org
Cc: dri-devel at lists.freedesktop.org
Cc: imx at lists.linux.dev
Cc: linux-arm-kernel at lists.infradead.org
---
 drivers/gpu/drm/panthor/panthor_gpu.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index 671049020afaa..0f07ef7d9aea7 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -470,11 +470,12 @@ int panthor_gpu_soft_reset(struct panthor_device *ptdev)
  */
 void panthor_gpu_suspend(struct panthor_device *ptdev)
 {
-	/* On a fast reset, simply power down the L2. */
-	if (!ptdev->reset.fast)
-		panthor_gpu_soft_reset(ptdev);
-	else
-		panthor_gpu_power_off(ptdev, L2, 1, 20000);
+	/*
+	 * Power off the L2 and soft reset the GPU, that makes
+	 * iMX95 Mali G310 resume without firmware boot timeout.
+	 */
+	panthor_gpu_power_off(ptdev, L2, 1, 20000);
+	panthor_gpu_soft_reset(ptdev);
 
 	panthor_gpu_irq_suspend(&ptdev->gpu->irq);
 }
-- 
2.47.2