On 06/02/2015 09:07 PM, Laura Abbott wrote: > Currently, the warning for missing device_caps gives a backtrace like so: > > [<ffffffff8175c199>] dump_stack+0x45/0x57 > [<ffffffff8109ad5a>] warn_slowpath_common+0x8a/0xc0 > [<ffffffff8109ae8a>] warn_slowpath_null+0x1a/0x20 > [<ffffffffa0237453>] v4l_querycap+0x43/0x80 [videodev] > [<ffffffffa0237734>] __video_do_ioctl+0x2a4/0x320 [videodev] > [<ffffffff812207e5>] ? do_last+0x195/0x1210 > [<ffffffffa023a11e>] video_usercopy+0x22e/0x5b0 [videodev] > [<ffffffffa0237490>] ? v4l_querycap+0x80/0x80 [videodev] > [<ffffffffa023a4b5>] video_ioctl2+0x15/0x20 [videodev] > [<ffffffffa0233733>] v4l2_ioctl+0x113/0x150 [videodev] > [<ffffffff81225798>] do_vfs_ioctl+0x2f8/0x4f0 > [<ffffffff8113b2d4>] ? __audit_syscall_entry+0xb4/0x110 > [<ffffffff81022d7c>] ? do_audit_syscall_entry+0x6c/0x70 > [<ffffffff81225a11>] SyS_ioctl+0x81/0xa0 > [<ffffffff8113b526>] ? __audit_syscall_exit+0x1f6/0x2a0 > [<ffffffff81763549>] system_call_fastpath+0x12/0x17 > > This indicates that device_caps are missing but doesn't give > much of a clue which driver is actually at fault. Improve > the warning output by showing the capabilities and which > operations set the capabilities. > > Signed-off-by: Laura Abbott <labbott@xxxxxxxxxxxxxxxxx> > --- > drivers/media/v4l2-core/v4l2-ioctl.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index aa407cb..e509608 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -1023,8 +1023,9 @@ static int v4l_querycap(const struct v4l2_ioctl_ops *ops, > * Drivers MUST fill in device_caps, so check for this and > * warn if it was forgotten. > */ > - WARN_ON(!(cap->capabilities & V4L2_CAP_DEVICE_CAPS) || > - !cap->device_caps); > + WARN(!(cap->capabilities & V4L2_CAP_DEVICE_CAPS) || > + !cap->device_caps, "Bad caps for ops %pS, %x %x", > + ops, cap->capabilities, cap->device_caps); Why not just print cap->driver? Much simpler and it always works! Regards, Hans > cap->device_caps |= V4L2_CAP_EXT_PIX_FORMAT; > > return ret; > -- 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
