On 08/12/2012 06:28 PM, Mauro Carvalho Chehab wrote:
Em 09-08-2012 19:25, Antti Palosaari escreveu:
Demodulator cannot perform statistic IOCTLs when it is not tuned.
Return -EPERM in such case.
While, in general, doing it makes sense, -EPERM is a very bad return code.
It is used to indicate when accessing some resources would require root access.
OK, makes sense. As I mentioned in coder letter I selected that due to
V4L2 usage to keep consistent.
VIDIOC_DECODER_CMD, VIDIOC_TRY_DECODER_CMD
VIDIOC_ENCODER_CMD, VIDIOC_TRY_ENCODER_CMD
Cover letter also lists all the other error codes I found suitable.
Which one you prefer?
Signed-off-by: Antti Palosaari <crope@xxxxxx>
---
drivers/media/dvb/dvb-core/dvb_frontend.c | 34 +++++++++++++++++++++++--------
1 file changed, 25 insertions(+), 9 deletions(-)
diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index 4fc11eb..40efcde 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -2157,27 +2157,43 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
err = fe->ops.read_status(fe, status);
break;
}
+
case FE_READ_BER:
- if (fe->ops.read_ber)
- err = fe->ops.read_ber(fe, (__u32*) parg);
+ if (fe->ops.read_ber) {
+ if (fepriv->thread)
+ err = fe->ops.read_ber(fe, (__u32 *) parg);
+ else
+ err = -EPERM;
+ }
break;
case FE_READ_SIGNAL_STRENGTH:
- if (fe->ops.read_signal_strength)
- err = fe->ops.read_signal_strength(fe, (__u16*) parg);
+ if (fe->ops.read_signal_strength) {
+ if (fepriv->thread)
+ err = fe->ops.read_signal_strength(fe, (__u16 *) parg);
+ else
+ err = -EPERM;
+ }
break;
Signal strength can still be available even without locking.
So it is correct. :)
It checks if frontend thread is running, not demodulator lock flags.
Actually, my original plan was to use demod lock flags but after looking
various demod drivers I ended-up conclusion it is not wise. Many demod
drivers just set all flags at the same time when there is full lock
gained and never provide more accurate info - all or nothing.
Anyhow, that solution prevents I/O errors when demod is so deep sleep
state (like reset) it cannot even answer at all.
case FE_READ_SNR:
- if (fe->ops.read_snr)
- err = fe->ops.read_snr(fe, (__u16*) parg);
+ if (fe->ops.read_snr) {
+ if (fepriv->thread)
+ err = fe->ops.read_snr(fe, (__u16 *) parg);
+ else
+ err = -EPERM;
+ }
break;
case FE_READ_UNCORRECTED_BLOCKS:
- if (fe->ops.read_ucblocks)
- err = fe->ops.read_ucblocks(fe, (__u32*) parg);
+ if (fe->ops.read_ucblocks) {
+ if (fepriv->thread)
+ err = fe->ops.read_ucblocks(fe, (__u32 *) parg);
+ else
+ err = -EPERM;
+ }
break;
-
case FE_DISEQC_RESET_OVERLOAD:
if (fe->ops.diseqc_reset_overload) {
err = fe->ops.diseqc_reset_overload(fe);
Regards,
Mauro
regards
Antti
--
http://palosaari.fi/
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