On 15.04.2010 22:21, Manu Abraham wrote:
> Hi Klaus,
>
> On Sun, Apr 11, 2010 at 1:12 PM, Klaus Schmidinger
> <klaus.schmidin...@tvdr.de> wrote:
>> The enum fe_caps provides flags that allow an application to detect
>> whether a device is capable of handling various modulation types etc.
>> A flag for detecting PSK_8, however, is missing.
>> This patch adds the flag FE_CAN_PSK_8 to frontend.h and implements
>> it for the gp8psk-fe.c and cx24116.c driver (apparently the only ones
>> with PSK_8). Only the gp8psk-fe.c has been explicitly tested, though.
>
>
> The FE_CAN_PSK_8 is a misnomer. In fact what you are looking for is
> FE_CAN_TURBO_FEC
Well, when processing the NIT data in VDR, for instance, the possible
modulation types that can be used according to the driver's frontend.h
are
QPSK,
QAM_16,
QAM_32,
QAM_64,
QAM_128,
QAM_256,
QAM_AUTO,
VSB_8,
VSB_16,
PSK_8,
APSK_16,
APSK_32,
DQPSK,
There is nothing in frontend.h that would be in any way related to
"turbo fec" (whatever that may be).
Of course we can rename FE_CAN_PSK_8 to FE_CAN_TURBO_FEC, but wouldn't
something like
if (Modulation == PSK_8 && !(frontendInfo.caps & FE_CAN_TURBO_FEC))
return false;
be even more irritating than a straight forward
if (Modulation == PSK_8 && !(frontendInfo.caps & FE_CAN_PSK_8))
return false;
After all it's
if (Modulation == QAM_256 && !(frontendInfo.caps & FE_CAN_QAM_256))
return false;
Please advise. Whatever you prefer is fine with me.
All I need in VDR is a flag that allows me to detect whether a device
can handle a given transponder's modulation. I don't really care how
that flag is named ;-).
> FE_CAN_8PSK will be matched by any DVB-S2 capable frontend, so that
> name is very likely to cause a very large confusion.
I chose FE_CAN_PSK_8 over FE_CAN_8PSK, because the modulation itself
is named PSK_8. This allows for easily finding all PSK_8 related places
with 'grep'. Personally I find the FE_CAN_8VSB and FE_CAN_16VSB misnomers,
because the modulations are named VSB_8 and VSB_16, respectively. They
should have been named FE_CAN_VSB_8 and FE_CAN_VSB_16 in the first place.
But that's, of course, a different story...
Klaus Schmidinger
> Another thing I am not entirely sure though ... The cx24116 requires a
> separate firmware and maybe some necessary code changes (?) for Turbo
> FEC to be supported, so I wonder whether applying the flag to the
> cx24116 driver would be any relevant....
>
> With regards to the Genpix driver, i guess the flag would be necessary.
>
>> Signed-off-by: Klaus Schmidinger <klaus.schmidin...@tvdr.de>
>> Tested-by: Derek Kelly <user....@gmail.com>
>
> Other than for the naming of the Flag (which i suggest strongly to
> update the patch) and the application to the cx24116 driver, it looks
> appropriate;
>
> Acked-by: Manu Abraham <m...@linuxtv.org>
>
>
>
>
>>
>> --- linux/include/linux/dvb/frontend.h.001 2010-04-05
>> 16:13:08.000000000 +0200
>> +++ linux/include/linux/dvb/frontend.h 2010-04-10 12:08:47.000000000 +0200
>> @@ -62,6 +62,7 @@
>> FE_CAN_8VSB = 0x200000,
>> FE_CAN_16VSB = 0x400000,
>> FE_HAS_EXTENDED_CAPS = 0x800000, /* We need more
>> bitspace for newer APIs, indicate this. */
>> + FE_CAN_PSK_8 = 0x8000000, /* frontend supports
>> "8psk modulation" */
>> FE_CAN_2G_MODULATION = 0x10000000, /* frontend supports
>> "2nd generation modulation" (DVB-S2) */
>> FE_NEEDS_BENDING = 0x20000000, /* not supported
>> anymore, don't use (frontend requires frequency bending) */
>> FE_CAN_RECOVER = 0x40000000, /* frontend can recover
>> from a cable unplug automatically */
>> --- linux/drivers/media/dvb/dvb-usb/gp8psk-fe.c.001 2010-04-05
>> 16:13:08.000000000 +0200
>> +++ linux/drivers/media/dvb/dvb-usb/gp8psk-fe.c 2010-04-10
>> 12:18:37.000000000 +0200
>> @@ -349,7 +349,7 @@
>> * FE_CAN_QAM_16 is for compatibility
>> * (Myth incorrectly detects Turbo-QPSK as plain
>> QAM-16)
>> */
>> - FE_CAN_QPSK | FE_CAN_QAM_16
>> + FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_PSK_8
>> },
>>
>> .release = gp8psk_fe_release,
>> --- linux/drivers/media/dvb/frontends/cx24116.c.001 2010-04-05
>> 16:13:08.000000000 +0200
>> +++ linux/drivers/media/dvb/frontends/cx24116.c 2010-04-10
>> 13:40:32.000000000 +0200
>> @@ -1496,7 +1496,7 @@
>> FE_CAN_FEC_4_5 | FE_CAN_FEC_5_6 | FE_CAN_FEC_6_7 |
>> FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
>> FE_CAN_2G_MODULATION |
>> - FE_CAN_QPSK | FE_CAN_RECOVER
>> + FE_CAN_QPSK | FE_CAN_RECOVER | FE_CAN_PSK_8
>> },
>>
>> .release = cx24116_release,
--
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