Re: em28xx list_add corruption reported by list debug

[Antti Palosaari <crope@iki.fi>]

On 22.12.2013 18:17, Antti Palosaari wrote:
> On 22.12.2013 17:55, Mauro Carvalho Chehab wrote:
>> Em Sun, 22 Dec 2013 13:06:00 -0200
>> Mauro Carvalho Chehab <m.chehab@samsung.com> escreveu:
>>
>>> Em Sun, 22 Dec 2013 00:27:21 +0200
>>> Antti Palosaari <crope@iki.fi> escreveu:
>>>
>>>> I ran also this kind of bug. Device was PCTV 290e, which has that video
>>>> unused. I have no any analog em28xx webcam to test if that happens
>>>> here too.
>>>>
>>>> Fortunately I found one video device which does not crash nor dump
>>>> debug
>>>> bug warnings. It is some old gspca webcam. Have to look example how
>>>> those videobuf callbacks are implemented there..
>>>>
>>>> regards
>>>> Antti
>>>>
>>>>
>>>> [crope@localhost linux]$ cat /dev/video0
>>>> cat: /dev/video0: Invalid argument
>>>> [crope@localhost linux]$ cat /dev/video0
>>>> cat: /dev/video0: Device or resource busy
>>>> [crope@localhost linux]$
>>>>
>>>>
>>>> joulu 22 00:08:24 localhost.localdomain kernel: em28174 #0: no endpoint
>>>> for analog mode and transfer type 0
>>>
>>> It seems that there's something bad on em28174 registration: it
>>> should not
>>> be creating a v4l2 device, if the device is DVB only.
>>>
>>> The thing is that, when this driver was created, all devices were either
>>> analog only or hybrid. Only very recently, pure DVB devices got added.
>>>
>>> It shouldn't be that hard to split em28xx_init_dev() into a few routines
>>> that would only register v4l2 if the device has analog support.
>>>
>>> Again, this changeset:
>>>     https://patchwork.linuxtv.org/patch/17967/
>>>
>>> Seems to be part of such solution, as it already splits the v4l2
>>> register logic into a separate function.
>>
>> Ok, if I didn't make any mistake, this changeset should do the trick:
>>     https://patchwork.linuxtv.org/patch/21282/
>>
>> Please notice that this is compile-tested only.
>
> I started to testing that patch, but now I get following compilation
> errors:
>
> WARNING: "em28xx_detect_sensor" [drivers/media/usb/em28xx/em28xx.ko]
> undefined!
> WARNING: "em28xx_init_camera" [drivers/media/usb/em28xx/em28xx.ko]
> undefined!
> WARNING: "em28xx_resolution_set"
> [drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
> WARNING: "em28xx_colorlevels_set_default"
> [drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
> WARNING: "em28xx_set_outfmt" [drivers/media/usb/em28xx/em28xx-v4l.ko]
> undefined!
> WARNING: "em28xx_read_reg_req_len"
> [drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
> WARNING: "em28xx_wake_i2c" [drivers/media/usb/em28xx/em28xx-v4l.ko]
> undefined!
> WARNING: "em28xx_set_alternate" [drivers/media/usb/em28xx/em28xx-v4l.ko]
> undefined!
> WARNING: "em28xx_vbi_supported" [drivers/media/usb/em28xx/em28xx-v4l.ko]
> undefined!
> WARNING: "em28xx_release_resources"
> [drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
> WARNING: "em28xx_boards" [drivers/media/usb/em28xx/em28xx-v4l.ko]
> undefined!
>
> anyhow, I am not sure if those are related or not. I will re-compile
> whole kernel to see (build only media).

It builds very fast as compile caching. Errors are still there. My tree 
is latest media/master + my SDR patches.

CRC d20c387c
Kernel: arch/x86/boot/bzImage is ready  (#78)
ERROR: "em28xx_detect_sensor" [drivers/media/usb/em28xx/em28xx.ko] 
undefined!
ERROR: "em28xx_init_camera" [drivers/media/usb/em28xx/em28xx.ko] undefined!
ERROR: "em28xx_resolution_set" [drivers/media/usb/em28xx/em28xx-v4l.ko] 
undefined!
ERROR: "em28xx_colorlevels_set_default" 
[drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
ERROR: "em28xx_set_outfmt" [drivers/media/usb/em28xx/em28xx-v4l.ko] 
undefined!
ERROR: "em28xx_read_reg_req_len" 
[drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
ERROR: "em28xx_wake_i2c" [drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
ERROR: "em28xx_set_alternate" [drivers/media/usb/em28xx/em28xx-v4l.ko] 
undefined!
ERROR: "em28xx_vbi_supported" [drivers/media/usb/em28xx/em28xx-v4l.ko] 
undefined!
ERROR: "em28xx_release_resources" 
[drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
ERROR: "em28xx_boards" [drivers/media/usb/em28xx/em28xx-v4l.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

regards
Antti

-- 
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