[Intel-gfx] [PATCH 3/7] drm/i915/skl: Refuse to load outdated dmc firmware

[Mika Kuoppala]

There is known issue on GT interrupt delivery with DC6 and
firmwares <1.21. There is a suspicion that this causes
spurious gpu hangs on driver init and with some workloads,
as upgrading the firmware to 1.21 makes these problems
disappear.

As of now the current version included in distribution
firmware packages is very like to be 1.19. Play it safe and
refuse to load a firmware version that may affect gpu
side stability.

With < 1.23 there is a palette and dmc ram corruption issue
so blacklist anything below that.

v2: Refuse to load fw instead of notifying the user
v3: Rebase on header version changes
v4: Refuse to load anything less than 1.23

Cc: Animesh Manna <animesh.manna at intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Dave Gordon <david.s.gordon at intel.com>
Cc: Arun Siluvery <arun.siluvery at linux.intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at gmail.com>
References: https://01.org/linuxgraphics/downloads/skldmcver121
References: https://01.org/linuxgraphics/downloads/skylake-dmc-1.23
Testcase: igt/gem_exec_nop
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/intel_csr.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
index cabcc51..85261d4 100644
--- a/drivers/gpu/drm/i915/intel_csr.c
+++ b/drivers/gpu/drm/i915/intel_csr.c
@@ -47,6 +47,9 @@
 MODULE_FIRMWARE(I915_CSR_SKL);
 MODULE_FIRMWARE(I915_CSR_BXT);
 
+#define SKL_REQUIRED_FW_MAJOR	1
+#define SKL_REQUIRED_FW_MINOR	23
+
 /*
 * SKL CSR registers for DC5 and DC6
 */
@@ -401,6 +404,14 @@ static void finish_csr_load(const struct firmware *fw, void *context)
 	dmc_payload = csr->dmc_payload;
 	memcpy(dmc_payload, &fw->data[readcount], nbytes);
 
+	if (IS_SKYLAKE(dev) &&
+	    (CSR_VERSION_MAJOR(csr->version) < SKL_REQUIRED_FW_MAJOR ||
+	     CSR_VERSION_MINOR(csr->version) < SKL_REQUIRED_FW_MINOR)) {
+		DRM_INFO("Outdated dmc firmware found, please upgrade to %u.%u or newer\n",
+			 SKL_REQUIRED_FW_MAJOR, SKL_REQUIRED_FW_MINOR);
+		goto out;
+	}
+
 	/* load csr program during system boot, as needed for DC states */
 	intel_csr_load_program(dev);
 	fw_loaded = true;
-- 
2.1.4