patch "staging: bcm2835-camera: Restore return behavior of" added to staging-next

This is a note to let you know that I've just added the patch titled

staging: bcm2835-camera: Restore return behavior of

to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-next branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release during the merge window.

If you have any questions about this process, please let me know.

From f816db1dc17b99b059325f41ed5a78f85d15368c Mon Sep 17 00:00:00 2001
From: Stefan Wahren <[email protected]>
Date: Wed, 26 Jun 2019 17:48:11 +0200
Subject: staging: bcm2835-camera: Restore return behavior of
ctrl_set_bitrate()

The commit 52c4dfcead49 ("Staging: vc04_services: Cleanup in ctrl_set_bitrate()") changed the return behavior of ctrl_set_bitrate(). We cannot do this because of a bug in the firmware, which breaks probing of bcm2835-camera:

bcm2835-v4l2: mmal_init: failed to set all camera controls: -3
Cleanup: Destroy video encoder
Cleanup: Destroy image encoder
Cleanup: Destroy video render
Cleanup: Destroy camera
bcm2835-v4l2: bcm2835_mmal_probe: mmal init failed: -3
bcm2835-camera: probe of bcm2835-camera failed with error -3

So restore the old behavior, add an explaining comment and a debug message to verify that the bug has been fixed in firmware.

---
 .../vc04_services/bcm2835-camera/controls.c   | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

index d60e378bdfce..c251164655ba 100644
@@ -604,15 +604,28 @@ static int ctrl_set_bitrate(struct bm2835_mmal_dev *dev,
 			    struct v4l2_ctrl *ctrl,
 			    const struct bm2835_mmal_v4l2_ctrl *mmal_ctrl)
 {
+	int ret;
 	struct vchiq_mmal_port *encoder_out;
 
 	dev->capture.encode_bitrate = ctrl->val;
 
 	encoder_out = &dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->output[0];
 
-	return vchiq_mmal_port_parameter_set(dev->instance, encoder_out,
-					     mmal_ctrl->mmal_id, &ctrl->val,
-					     sizeof(ctrl->val));
+	ret = vchiq_mmal_port_parameter_set(dev->instance, encoder_out,
+					    mmal_ctrl->mmal_id, &ctrl->val,
+					    sizeof(ctrl->val));
+
+	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
+		 "%s: After: mmal_ctrl:%p ctrl id:0x%x ctrl val:%d ret %d(%d)\n",
+		 __func__, mmal_ctrl, ctrl->id, ctrl->val, ret,
+		 (ret == 0 ? 0 : -EINVAL));
+
+	/*
+	 * Older firmware versions (pre July 2019) have a bug in handling
+	 * MMAL_PARAMETER_VIDEO_BIT_RATE that result in the call
+	 * returning -MMAL_MSG_STATUS_EINVAL. So ignore errors from this call.
+	 */
+	return 0;
 }
 
 static int ctrl_set_bitrate_mode(struct bm2835_mmal_dev *dev,

2.22.0