[PATCH] drm/amdgpu/vcn: Disable indirect SRAM on Vangogh broken BIOSes

[Guilherme G. Piccoli]

The VCN firmware loading path enables the indirect SRAM mode if it's
advertised as supported. We might have some cases of FW issues that
prevents this mode to working properly though, ending-up in a failed
probe. An example below, observed in the Steam Deck:

[...]
[drm] failed to load ucode VCN0_RAM(0x3A)
[drm] psp gfx command LOAD_IP_FW(0x6) failed and response status is (0xFFFF0000)
amdgpu 0000:04:00.0: [drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring vcn_dec_0 test failed (-110)
[drm:amdgpu_device_init.cold [amdgpu]] *ERROR* hw_init of IP block <vcn_v3_0> failed -110
amdgpu 0000:04:00.0: amdgpu: amdgpu_device_ip_init failed
amdgpu 0000:04:00.0: amdgpu: Fatal error during GPU init
[...]

Disabling the VCN block circumvents this, but it's a very invasive
workaround that turns off the entire feature. So, let's add a quirk
on VCN loading that checks for known problematic BIOSes on Vangogh,
so we can proactively disable the indirect SRAM mode and allow the
HW proper probe and VCN IP block to work fine.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2385
Fixes: 82132ecc5432 ("drm/amdgpu: enable Vangogh VCN indirect sram mode")
Cc: stable at vger.kernel.org
Cc: James Zhu <James.Zhu at amd.com>
Cc: Leo Liu <leo.liu at amd.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli at igalia.com>
---


Hi folks, based on the feedback from the gitlab issue, here is the upstream
attempt to quirk the Steam Deck's BIOSes having known issues with the
indirect SRAM mode. I've tested it on both the quirked BIOSes, and also
with some working ones. This patch is based on agd5f/amd-staging-drm-next.

Thanks in advance for reviews!
Cheers,

Guilherme


 drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
index 02d428ddf2f8..dc4f3f4cb644 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
@@ -26,6 +26,7 @@
 
 #include <linux/firmware.h>
 #include <linux/module.h>
+#include <linux/dmi.h>
 #include <linux/pci.h>
 #include <linux/debugfs.h>
 #include <drm/drm_drv.h>
@@ -114,6 +115,24 @@ int amdgpu_vcn_sw_init(struct amdgpu_device *adev)
 	    (adev->pg_flags & AMD_PG_SUPPORT_VCN_DPG))
 		adev->vcn.indirect_sram = true;
 
+	/*
+	 * Some Steam Deck's BIOS versions are incompatible with the
+	 * indirect SRAM mode, leading to amdgpu being unable to get
+	 * properly probed (and even potentially crashing the kernel).
+	 * Hence, check for these versions here - notice this is
+	 * restricted to Vangogh (Deck's APU).
+	 */
+	if (adev->ip_versions[UVD_HWIP][0] == IP_VERSION(3, 0, 2)) {
+		const char *bios_ver = dmi_get_system_info(DMI_BIOS_VERSION);
+
+		if (bios_ver && (!strncmp("F7A0113", bios_ver, 7) ||
+		     !strncmp("F7A0114", bios_ver, 7))) {
+			adev->vcn.indirect_sram = false;
+			dev_info(adev->dev,
+				"Steam Deck quirk: indirect SRAM disabled on BIOS %s\n", bios_ver);
+		}
+	}
+
 	hdr = (const struct common_firmware_header *)adev->vcn.fw->data;
 	adev->vcn.fw_version = le32_to_cpu(hdr->ucode_version);
 
-- 
2.39.2