[PATCH] media: atomisp: fix querycap initialization logic

[Mauro Carvalho Chehab]

Some recent changes at V4L2 core changed the way querycap is handled.

Due to that, this warning is generated:

	WARNING: CPU: 1 PID: 503 at drivers/media/v4l2-core/v4l2-dev.c:885 __video_register_device+0x93e/0x1120 [videodev]

as introduced by this commit:

	commit 3c1350501c21db8e3b1a38d9e97db29694305c3b
	Author: Hans Verkuil <hverkuil-cisco at xs4all.nl>
	Date:   Tue Jul 23 04:21:25 2019 -0400

	    media: v4l2-dev/ioctl: require non-zero device_caps, verify sane querycap results

	    Now that all V4L2 drivers set device_caps in struct video_device, we can add
	    a check for this to ensure all future drivers fill this in.

The fix is simple: we just need to initialize dev_caps before
registering the V4L2 dev.

While here, solve other problems at VIDIOC_QUERYCAP ioctl.

Reported-by: Patrik Gfeller <patrik.gfeller at gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei at kernel.org>
---
 .../staging/media/atomisp/pci/atomisp_ioctl.c | 21 ++++++-------------
 .../staging/media/atomisp/pci/atomisp_v4l2.c  |  4 ++++
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
index 3417cd547ae7..a5e71e5b714e 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
@@ -41,10 +41,8 @@
 
 #include "hrt/hive_isp_css_mm_hrt.h"
 
-/* for v4l2_capability */
 static const char *DRIVER = "atomisp";	/* max size 15 */
 static const char *CARD = "ATOM ISP";	/* max size 31 */
-static const char *BUS_INFO = "PCI-3";	/* max size 31 */
 
 /*
  * FIXME: ISP should not know beforehand all CIDs supported by sensor.
@@ -543,25 +541,18 @@ const struct atomisp_format_bridge *atomisp_get_format_bridge_from_mbus(
 /*
  * v4l2 ioctls
  * return ISP capabilities
- *
- * FIXME: capabilities should be different for video0/video2/video3
  */
 static int atomisp_querycap(struct file *file, void *fh,
 			    struct v4l2_capability *cap)
 {
-	memset(cap, 0, sizeof(struct v4l2_capability));
+	struct video_device *vdev = video_devdata(file);
+	struct atomisp_device *isp = video_get_drvdata(vdev);
 
-	WARN_ON(sizeof(DRIVER) > sizeof(cap->driver) ||
-		sizeof(CARD) > sizeof(cap->card) ||
-		sizeof(BUS_INFO) > sizeof(cap->bus_info));
+	strscpy(cap->driver, DRIVER, sizeof(cap->driver) - 1);
+	strscpy(cap->card, CARD, sizeof(cap->card) - 1);
+	snprintf(cap->bus_info, sizeof(cap->bus_info), "PCI:%s",
+		 pci_name(isp->pdev));
 
-	strncpy(cap->driver, DRIVER, sizeof(cap->driver) - 1);
-	strncpy(cap->card, CARD, sizeof(cap->card) - 1);
-	strncpy(cap->bus_info, BUS_INFO, sizeof(cap->card) - 1);
-
-	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
-			   V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_OUTPUT;
-	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
 	return 0;
 }
 
diff --git a/drivers/staging/media/atomisp/pci/atomisp_v4l2.c b/drivers/staging/media/atomisp/pci/atomisp_v4l2.c
index f1bae9712720..ce16e7824d33 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_v4l2.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_v4l2.c
@@ -548,6 +548,10 @@ int atomisp_video_register(struct atomisp_video_pipe *video,
 
 	video->vdev.v4l2_dev = vdev;
 
+	video->vdev.device_caps = V4L2_CAP_VIDEO_CAPTURE |
+				  V4L2_CAP_STREAMING |
+				  V4L2_CAP_VIDEO_OUTPUT;
+
 	ret = video_register_device(&video->vdev, VFL_TYPE_VIDEO, -1);
 	if (ret < 0)
 		dev_err(vdev->dev, "%s: could not register video device (%d)\n",
-- 
2.25.4