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>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index 49d95040096a..0223ad255cb4 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -1820,7 +1820,7 @@ 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 (fepriv->exit != DVB_FE_NO_EXIT)
@@ -1938,7 +1938,7 @@ static int dvb_frontend_ioctl_properties(struct file *file,
                 }
 
         } else
-                err = -ENOTTY;
+                err = -EOPNOTSUPP;
 
 out:
         kfree(tvp);
@@ -2071,7 +2071,7 @@ 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: {