drm/msm/adreno: deal with linux-firmware fw paths

When firmware was added to linux-firmware, it was put in a qcom sub-
directory, unlike what we'd been using before.  For a300_pfp.fw and
a300_pm4.fw symlinks were created, but we'd prefer not to have to do
this in the future.  So add support to look in both places when
loading firmware.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/adreno/a5xx_gpu.c

@@ -76,9 +76,26 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname)
 		goto out;
 	}
 
-	/* Load the rest of the MDT */
-	ret = qcom_mdt_load(dev, fw, fwname, GPU_PAS_ID, mem_region, mem_phys,
-		mem_size);
+	/*
+	 * Load the rest of the MDT
+	 *
+	 * Note that we could be dealing with two different paths, since
+	 * with upstream linux-firmware it would be in a qcom/ subdir..
+	 * adreno_request_fw() handles this, but qcom_mdt_load() does
+	 * not.  But since we've already gotten thru adreno_request_fw()
+	 * we know which of the two cases it is:
+	 */
+	if (to_adreno_gpu(gpu)->fwloc == FW_LOCATION_LEGACY) {
+		ret = qcom_mdt_load(dev, fw, fwname, GPU_PAS_ID,
+				mem_region, mem_phys, mem_size);
+	} else {
+		char newname[strlen("qcom/") + strlen(fwname) + 1];
+
+		sprintf(newname, "qcom/%s", fwname);
+
+		ret = qcom_mdt_load(dev, fw, newname, GPU_PAS_ID,
+				mem_region, mem_phys, mem_size);
+	}
 	if (ret)
 		goto out;
 

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -69,15 +69,72 @@ adreno_request_fw(struct adreno_gpu *adreno_gpu, const char *fwname)
 {
 	struct drm_device *drm = adreno_gpu->base.dev;
 	const struct firmware *fw = NULL;
+	char newname[strlen("qcom/") + strlen(fwname) + 1];
 	int ret;
 
-	ret = request_firmware(&fw, fwname, drm->dev);
-	if (ret) {
-		dev_err(drm->dev, "failed to load %s: %d\n", fwname, ret);
+	sprintf(newname, "qcom/%s", fwname);
+
+	/*
+	 * Try first to load from qcom/$fwfile using a direct load (to avoid
+	 * a potential timeout waiting for usermode helper)
+	 */
+	if ((adreno_gpu->fwloc == FW_LOCATION_UNKNOWN) ||
+	    (adreno_gpu->fwloc == FW_LOCATION_NEW)) {
+
+		ret = request_firmware_direct(&fw, newname, drm->dev);
+		if (!ret) {
+			dev_info(drm->dev, "loaded %s from new location\n",
+				newname);
+			adreno_gpu->fwloc = FW_LOCATION_NEW;
+			return fw;
+		} else if (adreno_gpu->fwloc != FW_LOCATION_UNKNOWN) {
+			dev_err(drm->dev, "failed to load %s: %d\n",
+				newname, ret);
 			return ERR_PTR(ret);
 		}
+	}
 
+	/*
+	 * Then try the legacy location without qcom/ prefix
+	 */
+	if ((adreno_gpu->fwloc == FW_LOCATION_UNKNOWN) ||
+	    (adreno_gpu->fwloc == FW_LOCATION_LEGACY)) {
+
+		ret = request_firmware_direct(&fw, fwname, drm->dev);
+		if (!ret) {
+			dev_info(drm->dev, "loaded %s from legacy location\n",
+				newname);
+			adreno_gpu->fwloc = FW_LOCATION_LEGACY;
 			return fw;
+		} else if (adreno_gpu->fwloc != FW_LOCATION_UNKNOWN) {
+			dev_err(drm->dev, "failed to load %s: %d\n",
+				fwname, ret);
+			return ERR_PTR(ret);
+		}
+	}
+
+	/*
+	 * Finally fall back to request_firmware() for cases where the
+	 * usermode helper is needed (I think mainly android)
+	 */
+	if ((adreno_gpu->fwloc == FW_LOCATION_UNKNOWN) ||
+	    (adreno_gpu->fwloc == FW_LOCATION_HELPER)) {
+
+		ret = request_firmware(&fw, newname, drm->dev);
+		if (!ret) {
+			dev_info(drm->dev, "loaded %s with helper\n",
+				newname);
+			adreno_gpu->fwloc = FW_LOCATION_HELPER;
+			return fw;
+		} else if (adreno_gpu->fwloc != FW_LOCATION_UNKNOWN) {
+			dev_err(drm->dev, "failed to load %s: %d\n",
+				newname, ret);
+			return ERR_PTR(ret);
+		}
+	}
+
+	dev_err(drm->dev, "failed to load %s\n", fwname);
+	return ERR_PTR(-ENOENT);
 }
 
 static int adreno_load_fw(struct adreno_gpu *adreno_gpu)

drivers/gpu/drm/msm/adreno/adreno_gpu.h

@@ -101,6 +101,27 @@ struct adreno_gpu {
 	/* interesting register offsets to dump: */
 	const unsigned int *registers;
 
+	/*
+	 * Are we loading fw from legacy path?  Prior to addition
+	 * of gpu firmware to linux-firmware, the fw files were
+	 * placed in toplevel firmware directory, following qcom's
+	 * android kernel.  But linux-firmware preferred they be
+	 * placed in a 'qcom' subdirectory.
+	 *
+	 * For backwards compatibility, we try first to load from
+	 * the new path, using request_firmware_direct() to avoid
+	 * any potential timeout waiting for usermode helper, then
+	 * fall back to the old path (with direct load).  And
+	 * finally fall back to request_firmware() with the new
+	 * path to allow the usermode helper.
+	 */
+	enum {
+		FW_LOCATION_UNKNOWN = 0,
+		FW_LOCATION_NEW,       /* /lib/firmware/qcom/$fwfile */
+		FW_LOCATION_LEGACY,    /* /lib/firmware/$fwfile */
+		FW_LOCATION_HELPER,
+	} fwloc;
+
 	/* firmware: */
 	const struct firmware *pm4, *pfp;