FAILED: patch "[PATCH] [media] ov2640: fix vflip control" failed to apply to 4.11-stable tree

The patch below does not apply to the 4.11-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Frank Schaefer <[email protected]>
Date: Sun, 16 Apr 2017 14:35:45 -0300
Subject: [PATCH] [media] ov2640: fix vflip control
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Enabling vflip currently causes wrong colors.
It seems that (at least with the current sensor setup) REG04_VFLIP_IMG only changes the vertical readout direction.
Because pixels are arranged RGRG... in odd lines and GBGB... in even lines, either a one line shift or even/odd line swap is required, too, but apparently this doesn't happen.

I finally figured out that this can be done manually by setting REG04_VREF_EN.
Looking at hflip, it turns out that bit REG04_HREF_EN is set there permanetly, but according to my tests has no effect on the pixel readout order.
So my conclusion is that the current documentation of sensor register 0x04 is wrong (has changed after preliminary datasheet version 2.2).

I'm pretty sure that automatic vertical line shift/switch can be enabled, too, but until anyone finds ot how this works, we have to stick with manual switching.

index 8acdb6098d3f..6709e4de12ca 100644
@@ -716,8 +716,10 @@ static int ov2640_s_ctrl(struct v4l2_ctrl *ctrl)
 
 	switch (ctrl->id) {
 	case V4L2_CID_VFLIP:
-		val = ctrl->val ? REG04_VFLIP_IMG : 0x00;
-		return ov2640_mask_set(client, REG04, REG04_VFLIP_IMG, val);
+		val = ctrl->val ? REG04_VFLIP_IMG | REG04_VREF_EN : 0x00;
+		return ov2640_mask_set(client, REG04,
+				       REG04_VFLIP_IMG | REG04_VREF_EN, val);
+		/* NOTE: REG04_VREF_EN: 1 line shift / even/odd line swap */
 	case V4L2_CID_HFLIP:
 		val = ctrl->val ? REG04_HFLIP_IMG : 0x00;
 		return ov2640_mask_set(client, REG04, REG04_HFLIP_IMG, val);