On Thu, 27 Feb 2025 17:58:06 +0100
Marek Vasut <marex@xxxxxxx> wrote:
> 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@xxxxxxx>
> ---
> Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Cc: Conor Dooley <conor+dt@xxxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
> Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: Sebastian Reichel <sre@xxxxxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Simona Vetter <simona@xxxxxxxx>
> Cc: Steven Price <steven.price@xxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: imx@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> ---
> 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);
Unfortunately, if you do that unconditionally we no longer have a
fast-reset. Would be good to figure out why the fast-reset doesn't work
on this platform.
