Em Thu, 27 May 2010 16:05:48 +0200 Guy Martin <gmsoft@xxxxxxxxxxxx> escreveu: > > Hi Mauro, > > > Sorry for the delay, I was abroad. > Let me detail the issue a bit more. > > In budget.c, the the frontend is attached this way : > > budget->dvb_frontend = dvb_attach(stv090x_attach, > &tt1600_stv090x_config, &budget->i2c_adap, STV090x_DEMODULATOR_0); > > This means that the tt1600_stv090x_config structure will be common for > all the cards. > > Then the tuner is attached to the frontend : > > ctl = dvb_attach(stv6110x_attach, budget->dvb_frontend, > &tt1600_stv6110x_config, &budget->i2c_adap); > > Once the tuner is attached, the ops are copied to the config : > tt1600_stv090x_config.tuner_sleep = ctl->tuner_sleep; > > This results in the ops being set for subsequently attached cards while > fe->tuner_priv is NULL. > > This is why a check for tuner_priv being set is mandatory when calling > tuner_sleep(). However as pointed out, it may not be the best fix. Ok. I'll commit it for now, as it is a simple patch and can be easily be applied at stable. The proper patch would be to avoid calling the function at the second board with tuner_priv = NULL. > > Regards, > Guy > > > > On Fri, 07 May 2010 22:26:13 -0300 > Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> wrote: > > > Manu Abraham wrote: > > > On Fri, May 7, 2010 at 4:39 PM, Mauro Carvalho Chehab > > > <mchehab@xxxxxxxxxx> wrote: > > >> Hi, > > >> > > > > > >> This is the summary of the patches that are currently under review. > > >> Each patch is represented by its submission date, the subject (up > > >> to 70 chars) and the patchwork link (if submitted via email). > > >> > > >> P.S.: This email is c/c to the developers that some review action > > >> is expected. > > >> > > >> May, 7 2010: [v2] stv6110x Fix kernel null pointer deref when > > >> plugging two TT s2-16 http://patchwork.kernel.org/patch/97612 > > > > > > > > > How is this patch going to fix a NULL ptr dereference when more > > > than 1 card is plugged in ? The patch doesn't seem to do what the > > > patch title implies. At least the patch title seems to be wrong. > > > Maybe the patch is supposed to check for a possible NULL ptr > > > dereference when put to sleep ? > > > > (c/c patch author, to be sure that he'll see your explanation request) > > > > His original patch is at: > > https://patchwork.kernel.org/patch/91929/ > > > > The original description with the bug were much better than version 2. > > > > From his OOPS log and description, I suspect that he's facing some > > sort of race condition with the two cards. > > > > This fix seems still valid (with an updated comment), as his dump > > proofed that there are some cases where fe->tuner_priv can be null, > > generating an OOPS, but it seems that his patch is combating > > the effect, and not the cause. > > > > So, I am for adding his patch for now, and then work on a more > > complete approach for the two cards environment. > > > -- Cheers, 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
