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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

While the changes reflect what is there at:

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

This reverts commit 177ffe5 ("[media] dvb_frontend: return -ENOTTY
for unimplement IOCTL").

Reported-by: Klaus Schmidinger <>
Signed-off-by: Mauro Carvalho Chehab <>
Signed-off-by: Linus Torvalds <>
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1 parent 11e7651 commit ac89758697195a8155f3861a34f0b41c6e562fcb Mauro Carvalho Chehab committed with Feb 15, 2013
Showing with 3 additions and 3 deletions.
  1. +3 −3 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;
@@ -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: {

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