upstream: Revert "[media] dvb_frontend: return -ENOTTY for unimplement IOCTL"

As reported by Klaus Schmidinger:
 "In VDR I use an ioctl() call with FE_READ_UNCORRECTED_BLOCKS on a
  device (using stb0899).  After this call I check 'errno' for
  EOPNOTSUPP to determine whether this device supports this call.  This
  used to work just fine, until a few months ago I noticed that my
  devices using stb0899 didn't display their signal quality in VDR's OSD
  any more.  After further investigation I found that
  ioctl(FE_READ_UNCORRECTED_BLOCKS) no longer returns EOPNOTSUPP, but
  rather ENOTTY.  And since I stop getting the signal quality in case
  any unknown errno value appears, this broke my signal quality query
  function."

While the changes reflect what is there at:

  http://comments.gmane.org/gmane.linux.kernel/1235728

it does cause regression on userspace.  So, revert it to stop the
damage.

This reverts commit 177ffe506cf8 ("[media] dvb_frontend: return -ENOTTY
for unimplement IOCTL").

Reported-by: Klaus Schmidinger <Klaus.Schmidinger@tvdr.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index f9cc2bc..6ce435a 100644 (file)
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -1900,7 +1900,7 @@ static int dvb_frontend_ioctl(struct file *file,
        struct dvb_frontend *fe = dvbdev->priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
-       int err = -ENOTTY;
+       int err = -EOPNOTSUPP;
 
        dev_dbg(fe->dvb->device, "%s: (%d)\n", __func__, _IOC_NR(cmd));
        if (down_interruptible(&fepriv->sem))
@@ -2022,7 +2022,7 @@ static int dvb_frontend_ioctl_properties(struct file *file,
                }
 
        } else
-               err = -ENOTTY;
+               err = -EOPNOTSUPP;
 
 out:
        kfree(tvp);
@@ -2155,7 +2155,7 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-       int err = -ENOTTY;
+       int err = -EOPNOTSUPP;
 
        switch (cmd) {
        case FE_GET_INFO: {