Re: em28xx submit of urb 0 failed (error=-27)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/14/2014 03:45 PM, Mauro Carvalho Chehab wrote:
Em Thu, 12 Jun 2014 03:37:26 +0300
Antti Palosaari <crope@xxxxxx> escreveu:

I just ran blind scan using w_scan and it interrupted scanning, with
following error (ioctl DMX_SET_FILTER failed: 27 File too large).

602000: (time: 00:58.973)
          (0.308sec): SCL (0x1F)
          (0.308sec) signal
          (0.308sec) lock
          signal ok:	QAM_AUTO f = 602000 kHz I999B8C999D999T999G999Y999
(0:0:0)
          initial PAT lookup..
start_filter:1644: ERROR: ioctl DMX_SET_FILTER failed: 27 File too large

regards
Antti


On 06/12/2014 03:23 AM, Antti Palosaari wrote:
Do you have any idea about that bug?
kernel: submit of urb 0 failed (error=-27)

https://bugzilla.kernel.org/show_bug.cgi?id=72891

I have seen it recently very often when I try start streaming DVB. When
it happens, device is unusable. I have feeling that it could be coming
from recent 28xx big changes where it was modularised. IIRC I reported
that at the time and Mauro added error number printing to log entry.
Anyhow, it is very annoying and occurs very often. And people have
started pinging me as I have added very many DVB devices to em28xx.

Well, according with USB documentation (Documentation/usb/URB.txt),
EFBIG means:
- Too many requested ISO frames

Perhaps the logic that calculates the number of URBs has a bug. In
the past, the URB size was hardcoded. Nowadays, em28xx dynamically
calculate it based on the USB descriptors, and the endpoints found.

 From what I know, different versions of em28xx chips have different
max limits. We need to identify on what chip version this error is
occurring, and reduce the number of ISOC frames there (with will
reduce the max bandwidth supported by such chip).

I tested these as having that issue:
em28178 PCTV tripleStick (292e)
em2874 MaxMedia UB425-TC
em2884 PCTV QuatroStick nano (520e)

Bug report mentions also:
em28174 PCTV nanoStick T2 (290e)
em28178 PCTV DVB-S2 Stick (461e)

So it must effect huge amount (if not all) of different em28xx chips used for DTV.


regards
Antti

--
http://palosaari.fi/
--
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




[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux