Re: [PATCH V1] media: mc-device.c: change media_device_request_alloc to match media_ioctl_info

From
Hans Verkuil <hidden>
Date
2020-08-06 11:05:14
Also in
linux-arm-kernel, linux-media
Reply to
unknown sender, 2020-08-06
On 06/08/2020 09:29, frederic.chen@mediatek.com wrote:
quoted hunk ↗ jump to hunk
From: Frederic Chen <redacted>

We modified the type of media_device_request_alloc()'s second
parameter from int* to void* so that it can match the interface
defined in struct media_ioctl_info.

Signed-off-by: Frederic Chen <redacted>
---
 drivers/media/mc/mc-device.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/media/mc/mc-device.c b/drivers/media/mc/mc-device.c
index da8088351135..bc5b5ecb6581 100644
--- a/drivers/media/mc/mc-device.c
+++ b/drivers/media/mc/mc-device.c
@@ -370,9 +370,10 @@ static long media_device_get_topology(struct media_device *mdev, void *arg)
 	return ret;
 }
 
-static long media_device_request_alloc(struct media_device *mdev,
-				       int *alloc_fd)
+static long media_device_request_alloc(struct media_device *mdev, void *arg)
 {
+	int *alloc_fd = arg;
+
 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
 		return -ENOTTY;
This change is fine, but the reason this wasn't noticed before is the cast in
the MEDIA_IOC_ARG define:

#define MEDIA_IOC_ARG(__cmd, func, fl, from_user, to_user)              \
        [_IOC_NR(MEDIA_IOC_##__cmd)] = {                                \
                .cmd = MEDIA_IOC_##__cmd,                               \
                .fn = (long (*)(struct media_device *, void *))func,    \
                .flags = fl,                                            \
                .arg_from_user = from_user,                             \
                .arg_to_user = to_user,                                 \
        }

When assigning to .fn the func is cast to a specific function prototype.
Without that cast the compiler would have warned about the mismatch.

I see no reason for that cast, so drop that cast as well.

Regards,

	Hans

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Thread (4 messages) 4 messages, 2 authors, last reply 2020-08-06
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