[PATCH 1/2] drm/xe/pm: Temporarily disable D3Cold on BMG

[Lucas De Marchi]

On Thu, Mar 06, 2025 at 04:36:14PM -0500, Rodrigo Vivi wrote:
>Currently, many instability cases related to D3Cold -> D0 transition
>on BMG are under investigation. Among them some bad cases where
>the device is lost after 1 to 3 transitions from D3Cold to D0
>on the runtime pm, with pcieport upstream bridge port link retrain
>failure.
>
>In other cases, it works fine, but with some sudden random memory
>corruptions after D3cold, that could be 0xffff missed ack on GT
>forcewake or GuC reload related failures.
>
>In some other cases though, D3Cold -> D0 works pretty reliably.
>It looks like it is a combination of GPU cards and Host boards at
>this point. So, there is no possible/available quirk at this time.
>
>This patch disables the D3Cold by default on BMG by reducing the
>vram_d3cold_threshold to 0. Users and developers who wants to enable
>it are still able to via
>$ echo 300 > /sys/bus/pci/devices/<addr>/vram_d3cold_threshold
>
>Fixes: 3adcf970dc7e ("drm/xe/bmg: Drop force_probe requirement")
>Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4037
>Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4395
>Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4396

are these Link: or should we use Closes: ?

>Cc: Karthik Poosa <karthik.poosa at intel.com>
>Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
>---
> drivers/gpu/drm/xe/xe_pm.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
>index 12200be7b43d..a9f61a5fc971 100644
>--- a/drivers/gpu/drm/xe/xe_pm.c
>+++ b/drivers/gpu/drm/xe/xe_pm.c
>@@ -287,6 +287,7 @@ ALLOW_ERROR_INJECTION(xe_pm_init_early, ERRNO); /* See xe_pci_probe() */
>  */
> int xe_pm_init(struct xe_device *xe)
> {
>+	u32 vram_threshold;
> 	int err;
>
> 	/* For now suspend/resume is only allowed with GuC */
>@@ -300,7 +301,11 @@ int xe_pm_init(struct xe_device *xe)
> 		if (err)
> 			return err;
>
>-		err = xe_pm_set_vram_threshold(xe, DEFAULT_VRAM_THRESHOLD);
>+		/* FIXME: D3Cold temporarily disabled by default on BMG */
>+		vram_threshold = xe->info.platform == XE_BATTLEMAGE ? 0 :
>+				DEFAULT_VRAM_THRESHOLD;

we usually have to extract this for different values per platform, so
maybe just go ahead and do that?

	u32 vram_threshold_value(struct xe_device *xe)
	{
		/* FIXME: D3Cold temporarily disabled by default on BMG */
		if (xe->info.platform == XE_BATTLEMAGE)
			return 0;

		return DEFAULT_VRAM_THRESHOLD;
	}

	xe_pm_init()
	{
		...
		vram_threshold = vram_threshold_value(xe);
	}

Then the second patch simply removes the first 3 lines of that function.
Anyway, I agree with the approach to get things working. We can try
enabling d3cold again when we understand what's going on.


Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>


for both patches.

thanks
Lucas De Marchi

>+
>+		err = xe_pm_set_vram_threshold(xe, vram_threshold);
> 		if (err)
> 			return err;
> 	}
>-- 
>2.48.1
>