From 542a56e8eb4467ae654eefab31ff194569db39cd Mon Sep 17 00:00:00 2001
From: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Date: Sun, 12 Mar 2023 13:51:00 -0300
Subject: [PATCH] drm/amdgpu/vcn: Disable indirect SRAM on Vangogh broken BIOSes
Git-commit: 542a56e8eb4467ae654eefab31ff194569db39cd
Patch-mainline: v6.3-rc3
References: git-fixes
Alt-commit: 1aff0a5d71d23be6658f893c88c6a9791202bcb1

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@vger.kernel.org
Cc: James Zhu <James.Zhu@amd.com>
Cc: Leo Liu <leo.liu@amd.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

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

--- 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>
@@ -222,6 +223,24 @@ int amdgpu_vcn_sw_init(struct amdgpu_dev
 		return r;
 	}
 
+	/*
+	 * 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);