Messages in this thread | | | Date | Mon, 21 Mar 2011 09:44:31 +0100 | From | Jiri Slaby <> | Subject | Re: PATCH: Leadtek DTVb1800H require longer delay for tuner reset |
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On 03/20/2011 11:05 PM, Mirek Slugeň wrote: > Hi, > > I am using alot of tuners Leadtek DTV1800H under Linux, minimum 5 > devices per one PC with kernel 2.6.37.4. I discovered bug which I can se > very often but not always. When device tuner is reseted there is not > enough time to do all needed stuff and sometimes (randomly) kernel show > this message: > > [ 821.369647] cx88[0]/1: IRQ loop detected, disabling interrupts > > Patch is again very simple, we need to adjust time in reset function > after cx_clear and cx_set calls from 50 to 75 us. I tested this patch on > 4 PC with similar problems and all are without this issue. > > M. Slugen > > > kernel_cx88_reset.diff > > > diff -Naur linux-2.6.37.4.old//drivers/media/video/cx88/cx88-cards.c linux-2.6.37.4/drivers/media/video/cx88/cx88-cards.c > --- linux-2.6.37.4.old//drivers/media/video/cx88/cx88-cards.c 2011-03-20 21:30:52.000000000 +0100 > +++ linux-2.6.37.4/drivers/media/video/cx88/cx88-cards.c 2011-03-20 22:25:54.710228001 +0100 > @@ -3019,9 +3019,9 @@ > cx_set(MO_GP1_IO, 0x1010); > mdelay(50); > cx_clear(MO_GP1_IO, 0x10); > - mdelay(50); > + mdelay(75); > cx_set(MO_GP1_IO, 0x10); > - mdelay(50); > + mdelay(75);
Wow, 75 ms of busy-waiting. Since others use msleep, all these should be converted to msleep too. Or is this an atomic context, so that the others are broken (e.g. cx88_dvico_xc2028_callback)?
Also for instance I don't understand this code: cx_write(MO_GP2_IO, 0xcf7); mdelay(50); cx_write(MO_GP2_IO, 0xef5); mdelay(50); cx_write(MO_GP2_IO, 0xcf7); msleep(10);
Delays of 50 ms and sleep of 10 ms? Given [um]delay spin _at least_ the time specified, what was the intention of this?
regards, -- js suse labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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