Hi Sakari,
Thank you for the patch.
On Wednesday 04 May 2016 14:20:54 Sakari Ailus wrote:
> New IOCTLs (especially for the request API) do not necessarily need the
> graph mutex acquired. Leave this up to the drivers.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/media/media-device.c | 47 +++++++++++++++++++++++-----------------
> 1 file changed, 28 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 39fe07f..8aef5b8 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -390,21 +390,26 @@ static long copy_arg_to_user_nop(void __user *uarg,
> void *karg, }
> #endif
>
> -#define MEDIA_IOC_ARG(__cmd, func, from_user, to_user) \
> - [_IOC_NR(MEDIA_IOC_##__cmd)] = { \
> - .cmd = MEDIA_IOC_##__cmd, \
> +/* Do acquire the graph mutex */
> +#define MEDIA_IOC_FL_GRAPH_MUTEX BIT(0)
> +
> +#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, \
> - .arg_from_user = from_user, \
> - .arg_to_user = to_user, \
> + .flags = fl, \
> + .arg_from_user = from_user, \
> + .arg_to_user = to_user, \
> }
>
> -#define MEDIA_IOC(__cmd, func)
\
> - MEDIA_IOC_ARG(__cmd, func, copy_arg_from_user, copy_arg_to_user)
> +#define MEDIA_IOC(__cmd, func, fl) \
> + MEDIA_IOC_ARG(__cmd, func, fl, copy_arg_from_user, copy_arg_to_user)
>
> /* the table is indexed by _IOC_NR(cmd) */
> struct media_ioctl_info {
> unsigned int cmd;
> long (*fn)(struct media_device *dev, void *arg);
> + unsigned short flags;
> long (*arg_from_user)(void *karg, void __user *uarg, unsigned int
cmd);
> long (*arg_to_user)(void __user *uarg, void *karg, unsigned int cmd);
> };
> @@ -449,9 +454,13 @@ static long __media_device_ioctl(
>
> info->arg_from_user(karg, arg, cmd);
>
> - mutex_lock(&dev->graph_mutex);
> + if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
> + mutex_lock(&dev->graph_mutex);
> +
> ret = info->fn(dev, karg);
> - mutex_unlock(&dev->graph_mutex);
> +
> + if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
> + mutex_unlock(&dev->graph_mutex);
>
> if (ret)
> return ret;
> @@ -460,11 +469,11 @@ static long __media_device_ioctl(
> }
>
> static const struct media_ioctl_info ioctl_info[] = {
> - MEDIA_IOC(DEVICE_INFO, media_device_get_info),
> - MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities),
> - MEDIA_IOC(ENUM_LINKS, media_device_enum_links),
> - MEDIA_IOC(SETUP_LINK, media_device_setup_link),
> - MEDIA_IOC(G_TOPOLOGY, media_device_get_topology),
> + MEDIA_IOC(DEVICE_INFO, media_device_get_info,
> MEDIA_IOC_FL_GRAPH_MUTEX),
do we really need to acquire the graph mutex for this ioctl ?
> + MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities,
> MEDIA_IOC_FL_GRAPH_MUTEX), + MEDIA_IOC(ENUM_LINKS, media_device_enum_links,
> MEDIA_IOC_FL_GRAPH_MUTEX), + MEDIA_IOC(SETUP_LINK, media_device_setup_link,
> MEDIA_IOC_FL_GRAPH_MUTEX), + MEDIA_IOC(G_TOPOLOGY,
> media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX), };
>
> static long media_device_ioctl(struct file *filp, unsigned int cmd,
> @@ -510,11 +519,11 @@ static long from_user_enum_links32(void *karg, void
> __user *uarg, #define MEDIA_IOC_ENUM_LINKS32 _IOWR('|', 0x02,
struct
> media_links_enum32)
>
> static const struct media_ioctl_info compat_ioctl_info[] = {
> - MEDIA_IOC(DEVICE_INFO, media_device_get_info),
> - MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities),
> - MEDIA_IOC_ARG(ENUM_LINKS32, media_device_enum_links,
> from_user_enum_links32, copy_arg_to_user_nop), - MEDIA_IOC(SETUP_LINK,
> media_device_setup_link),
> - MEDIA_IOC(G_TOPOLOGY, media_device_get_topology),
> + MEDIA_IOC(DEVICE_INFO, media_device_get_info,
MEDIA_IOC_FL_GRAPH_MUTEX),
> + MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities,
> MEDIA_IOC_FL_GRAPH_MUTEX), + MEDIA_IOC_ARG(ENUM_LINKS32,
> media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX, from_user_enum_links32,
> copy_arg_to_user_nop), + MEDIA_IOC(SETUP_LINK, media_device_setup_link,
> MEDIA_IOC_FL_GRAPH_MUTEX), + MEDIA_IOC(G_TOPOLOGY,
> media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX), };
>
> static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
--
Regards,
Laurent Pinchart
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
