Re: [PATCH 0/5] dvb-frontend statistic IOCTL validation

[Antti Palosaari <crope@iki.fi>]

On 08/16/2012 03:28 AM, Antti Palosaari wrote:
> Take two.
>
> I added some logic to prevent statistic queries in case demodulator is clearly in state statistic query is invalid. Currently there could be checks in device driver but usually not. Gar
> bage is usually returned and in some cases even I/O errors are generated as demod is put sleep and cannot answer any request.
>
> I changed error code EPERM to EAGAIN. What I looked existing demodulator drivers there was multiple error codes used. EAGAIN was one, at least DRX-K uses it.

oops, this could be understood wrong. Originally no standardized error 
code at all, it was responsibility of each driver to return what they 
wish - and surely they did it :]

EPERM was used first version of that patch series, but got feedback from 
Mauro it is not suitable as it is documented:
"Permission denied. Can be returned if the device needs write 
permission, or some special capabilities is needed (e. g. root)"

Thus EAGAIN. Hope this is now better.


>
> Also documentation is updated according to new situation.
>
> Antti Palosaari (5):
>    dvb_frontend: use Kernel dev_* logging
>    dvb_frontend: return -ENOTTY for unimplement IOCTL
>    dvb_frontend: do not allow statistic IOCTLs when sleeping
>    DocBook: update ioctl error codes EAGAIN, ENOSYS, EOPNOTSUPP
>    rtl2832: remove dummy callback implementations
>
>   Documentation/DocBook/media/v4l/gen-errors.xml |  12 +-
>   drivers/media/dvb-core/dvb_frontend.c          | 266 +++++++++++++------------
>   drivers/media/dvb-frontends/rtl2832.c          |  29 ---
>   3 files changed, 151 insertions(+), 156 deletions(-)
>


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