[PATCH 3/3] drm/msm/adreno: deal with linux-firmware fw paths

[Rob Clark]

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 at gmail.com>
---
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 64 ++++++++++++++++++++++++++++++---
 drivers/gpu/drm/msm/adreno/adreno_gpu.h | 21 +++++++++++
 2 files changed, 81 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 19e12380297e..dc0db660c617 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -69,12 +69,68 @@ 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);
-		return ERR_PTR(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);
+		}
 	}
 
 	return fw;
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index 3eda98af546e..b8c22658929d 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/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;
 
-- 
2.13.6