Hi Michael, On Monday 09 May 2011 14:32:09 Michael Jones wrote: > Hi Laurent, > > I can't find where the locking is handled for ISP subdev standard ioctls > like ccdc_v4l2_pad_ops.set_fmt(). Using the CCDC as an example, it > looks to me like the following sequence happens when e.g. format is set > on CCDC pad 0: > > 1. # media-ctl --set-format '"OMAP3 ISP CCDC":0 [Y8 640x480]' > > 2. v4l2-dev.c:v4l2_ioctl() > > this calls vdev->fops->unlocked_ioctl, which was set to > v4l2-subdev.c:subdev_ioctl() in "v4l2_subdev_fops" in > v4l2-device.c:v4l2_device_register_subdev_nodes() > > 3. v4l2-subdev.c:subdev_ioctl() > 4. video_usercopy() > 5. v4l2-ioctl.c:__video_usercopy() > 6. v4l2-subdev.c:subdev_do_ioctl() > 7. ispccdc.c:ccdc_set_format() > > ccdc_set_format() sets ccdc->formats[pad], access to which should be > serialized, but I don't see how this happens. In the call sequence > above, the only opportunity I see is in (2), but only then if > ccdc->subdev.devnode.lock is set, which doesn't seem to be done. > > Can you clarify this for me? What mutex is held during a call to > ccdc_set_format()? None. Patches are welcome :-) -- 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
