Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/dvb-frontends/stb0899_drv.c:540:1: warning: 'stb0899_write_regs' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer. Considering that I2C
transfers are generally limited, and that devices used on USB has a
max data length of 64 bytes for the control URBs.
So, it seem safe to use 64 bytes as the hard limit for all those devices.
On most cases, the limit is a way lower than that, but this limit
is small enough to not affect the Kernel stack, and it is a no brain
limit, as using smaller ones would require to either carefully each
driver or to take a look on each datasheet.
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
According with Manu Abraham, stb0899 seek algorithm is broken
for symbol rates bellow to 5Mbauds. So, revert those patches:
55b3318 [media] stb0899: allow minimum symbol rate of 2000000
2eeed77 [media] stb0899: allow minimum symbol rate of 1000000
Requested-by: Manu Abraham <abraham.manu@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Usually, inversion doesn't change in a system. Storing the last
successful inversion value speeds up tuning of DVB-S2 transponders.
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Looks like product datasheets for tuners containing STB0899 are
suggesting specification for min. symbol rate of 2MS/s.
Some specs found here, all suggesting 2MS/s for min. symbol rate:
Comtech DVBS2-6899
http://comtech.sg1002.myweb.hinet.net/pdf/dvbs2-6899.pdf
TechniSat SkyStar HD2
http://www.scaistar.com/skystar2/skystarhd2.htm
Azurewave AD-SP400
http://www.pulsat.com/products/AzureWave-AD%252dSP400-High-Definition-PC-Card.html
New patch:
This makes minimum symbol rate driver capabilities on par with some
accessible datasheet specifications*, and allows tuning on linux to
transponders that have symbol rate between 2000000-5000000, too.
Patch was tested successfully on Eutelsat 16A transponders that
became reachable with it (2000000 < symbol rate < 5000000):
* DVB/S 12507050 V 2532000 3/4
* DVB/S2 12574000 V 4355000 3/4 8PSK
* DVB/S 12593000 V 2500000 2/3
* DVB/S 12596940 V 2848000 2/3
* DVB/S 12600750 V 2500000 1/2
* DVB/S 12675590 H 4248000 3/4
(*) Datasheet: http://comtech.sg1002.myweb.hinet.net/pdf/dvbs2-6899.pdf
Maximum Symbol Rate
QPSK/LDPC/PCH: 20-30Mbps
8PSK/LDPC/BCH: 10-30Mbps
DVB: 2-45Mbps
^--------- min. symbol rate
Signed-off-by: Zoran Turalija <zoran.turalija@gmail.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This makes minimum symbol rate driver capabilities on par with
windows driver, and allows tuning on linux to transponders that
have symbol rate below 5000000, too.
Patch was tested successfully on Eutelsat 16A transponders that
became reachable with it (1000000 < symbol rate < 5000000):
* DVB/S 12507050 V 2532000 3/4
* DVB/S2 12574000 V 4355000 3/4 8PSK
* DVB/S 12593000 V 2500000 2/3
* DVB/S 12596940 V 2848000 2/3
* DVB/S 12600750 V 2500000 1/2
* DVB/S 12675590 H 4248000 3/4
Signed-off-by: Zoran Turalija <zoran.turalija@gmail.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Am 14.08.2012 14:05, schrieb Manu Abraham:
>> My other device, a STB0899, always reports the set frequency. So it seems
>> driver dependent whether it reports the actually locked frequency found by
>> the zig-zag-algorithm or just the set frequency to tune to.
>
> The STV0299 blindly sets the value based on a software zigzag (due to simpler
> hardware), but this might not be accurate enough. On the other hand, the
> STB0899 internally does zig-zag in hardware for DVB-S2, and partly in
> software for DVB-S.
>
> In any event, the get_frontend callback should return the value that is read
> from the demodulator registers, rather than the cached original value that
> which was requested to be tuned.
>
> The stb0899 returns only the cached value IIRC. Maybe I will fix this soon,
> or maybe you can send a patch.
This is what I get after the patch:
Sat. Pol. Band Freq (MHz) Set Freq (MHz) Get Delta (MHz)
S19,2E H L 10744 10748,474 4,474
S19,2E H L 10773 10777,944 4,944
S19,2E H L 10832 10836,953 4,953
S19,2E H L 10861 10868,774 7,774
...
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Cc: Manu Abraham <abraham.manu@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Raise the DVB frontends one level up, as the intention is to remove
the drivers/media/dvb directory.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
