Em Wed, 27 Jan 2016 22:27:41 +0100 Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: > On 01/27/2016 09:57 PM, Matthias Schwarzott wrote: > > Am 27.01.2016 um 13:08 schrieb Hans Verkuil: > >> The vb2_thread implementation was made generic and was moved from > >> videobuf2-v4l2.c to videobuf2-core.c in commit af3bac1a. Unfortunately > >> that clearly was never tested since it broke read() causing NULL address > >> references. > >> > >> The root cause was confused handling of vb2_buffer vs v4l2_buffer (the pb > >> pointer in various core functions). > >> > >> The v4l2_buffer no longer exists after moving the code into the core and > >> it is no longer needed. However, the vb2_thread code passed a pointer to > >> a vb2_buffer to the core functions were a v4l2_buffer pointer was expected > >> and vb2_thread expected that the vb2_buffer fields would be filled in > >> correctly. > >> > >> This is obviously wrong since v4l2_buffer != vb2_buffer. Note that the > >> pb pointer is a void pointer, so no type-checking took place. > >> > >> This patch fixes this problem: > >> > >> 1) allow pb to be NULL for vb2_core_(d)qbuf. The vb2_thread code will use > >> a NULL pointer here since they don't care about v4l2_buffer anyway. > >> 2) let vb2_core_dqbuf pass back the index of the received buffer. This is > >> all vb2_thread needs: this index is the index into the q->bufs array > >> and vb2_thread just gets the vb2_buffer from there. > >> 3) the fileio->b pointer (that originally contained a v4l2_buffer) is > >> removed altogether since it is no longer needed. > >> > >> Tested with vivid and the cobalt driver. > >> > >> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > >> Tested-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > >> Reported-by: Matthias Schwarzott <zzam@xxxxxxxxxx> > > > > Hi Hans! > > > > Thank you for this patch. > > I gave this patch a try on the latest sources from > > git://linuxtv.org/media_tree.git > > > > Compiled for kernel 4.2.8 with media_build. > > > > Now it no longer oopses. > > Good. > > > It tunes fine (according to femon), but I still do not get a > > picture/dvbtraffic reports nothing. > > I will try to do a DVB test tomorrow. I can't spend too much time on it so > if I can't reproduce it I'll probably ask Mauro to take a look. After tomorrow > it will take at least a week before I have another chance of testing this due > to traveling. There is one other unrelated bug, fixed on this patch: https://patchwork.linuxtv.org/patch/32814/ I added both patches on my experimental tree, together with a fix for tda10046 demod, at: https://git.linuxtv.org/mchehab/experimental.git/log/?h=vb2-dvb-fixup Please test. At least here, it is working fine: $ LANG=C ~/v4l-utils/utils/dvb/dvbv5-scan -Ichannel ~/dvbt-teste -F Cannot calc frequency shift. Either bandwidth/symbol-rate is unavailable (yet). Scanning frequency #1 562000000 Lock (0x1f) Signal= 70.20% C/N= 92.16% UCB= 60395 postBER= 8 Service D8, provider NTN: digital television Service BFM TV, provider NTN: digital television Service i>TELE, provider NTN: digital television Service D17, provider NTN: digital television Service Gulli, provider NTN: digital television Service France 4, provider NTN: digital television $ LANG=C ~/v4l-utils/utils/dvb/dvbv5-zap -Ichannel -c ~/dvbt-teste -m 562000000 PID FREQ SPEED TOTAL 0000 9.70 p/s 14.2 Kbps 12 KB 0010 2.14 p/s 3.1 Kbps 2 KB 0012 82.04 p/s 120.5 Kbps 105 KB 0015 1.85 p/s 2.7 Kbps 2 KB 006e 9.84 p/s 14.5 Kbps 12 KB 0078 2170.21 p/s 3187.5 Kbps 2792 KB 0082 130.26 p/s 191.3 Kbps 167 KB 0083 130.26 p/s 191.3 Kbps 167 KB 008c 2.43 p/s 3.6 Kbps 3 KB 008d 2.43 p/s 3.6 Kbps 3 KB 00aa 2.00 p/s 2.9 Kbps 2 KB 0136 9.84 p/s 14.5 Kbps 12 KB 0140 2864.03 p/s 4206.5 Kbps 3685 KB 014a 130.26 p/s 191.3 Kbps 167 KB 0154 2.57 p/s 3.8 Kbps 3 KB 019a 9.84 p/s 14.5 Kbps 12 KB 01a4 2316.16 p/s 3401.9 Kbps 2980 KB 01ae 130.12 p/s 191.1 Kbps 167 KB 01b8 2.43 p/s 3.6 Kbps 3 KB 01d6 2.00 p/s 2.9 Kbps 2 KB 01fe 9.84 p/s 14.5 Kbps 12 KB 0208 2276.22 p/s 3343.2 Kbps 2929 KB 0212 130.40 p/s 191.5 Kbps 167 KB 0213 130.40 p/s 191.5 Kbps 167 KB 021c 7.42 p/s 10.9 Kbps 9 KB 021d 2.57 p/s 3.8 Kbps 3 KB 0221 24.68 p/s 36.3 Kbps 31 KB 023a 2.00 p/s 2.9 Kbps 2 KB 0262 9.84 p/s 14.5 Kbps 12 KB 026c 2209.16 p/s 3244.7 Kbps 2842 KB 0276 130.26 p/s 191.3 Kbps 167 KB 0277 130.26 p/s 191.3 Kbps 167 KB 0280 2.43 p/s 3.6 Kbps 3 KB 0281 2.43 p/s 3.6 Kbps 3 KB 02c6 9.84 p/s 14.5 Kbps 12 KB 02d0 2187.76 p/s 3213.3 Kbps 2815 KB 02da 130.40 p/s 191.5 Kbps 167 KB 02db 130.40 p/s 191.5 Kbps 167 KB 02e4 2.57 p/s 3.8 Kbps 3 KB 02e5 2.57 p/s 3.8 Kbps 3 KB 0302 2.00 p/s 2.9 Kbps 2 KB 0303 177.20 p/s 260.3 Kbps 228 KB 1fff 5060.78 p/s 7433.0 Kbps 6512 KB TOT 20782.42 p/s 30524.2 Kbps 26743 KB Lock (0x1f) Signal= 70.20% C/N= 100.00% UCB= 65535 postBER= 24 Please test. I should be applying both patches tomorrow, in order to send them as quick as possible to 4.5-rc. Regards, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
