linux-stable.git/drivers/media/dvb, branch v3.0.2 Linux kernel stable tree [media] dvb_frontend: fix race condition in stopping/starting frontend 2011-07-13T22:50:12+00:00 Devin Heitmueller dheitmueller@kernellabs.com 2011-07-05T00:55:01+00:00 2d1969312d6319d28ae9609a84f969b6933bd51c Attached is a patch which addresses a race condition in the DVB core related to closing/reopening the DVB frontend device in quick succession. This is the reason that devices such as the HVR-1300, HVR-3000, and HVR-4000 have been failing to scan properly under MythTV and w_scan. The gory details of the race are described in the patch. Devin There is a race condition exhibited when channel scanners such as w_scan and MythTV quickly close and then reopen the frontend device node. Under normal conditions, the behavior is as follows: 1. Application closes the device node 2. DVB frontend ioctl calls dvb_frontend_release which sets fepriv->release_jiffies 3. DVB frontend thread *eventually* calls dvb_frontend_is_exiting() which compares fepriv->release_jiffies, and shuts down the thread if timeout has expired 4. Thread goes away 5. Application opens frontend device 6. DVB frontend ioctl() calls ts_bus_ctrl(1) 7. DVB frontend ioctl() creates new frontend thread, which calls dvb_frontend_init(), which has demod driver init() routine setup initial register state for demod chip. 8. Tuning request is issued. The race occurs when the application in step 5 performs the new open() call before the frontend thread is shutdown. In this case the ts_bus_ctrl() call is made, which strobes the RESET pin on the demodulator, but the dvb_frontend_init() function never gets called because the frontend thread hasn't gone away yet. As a result, the initial register config for the demod is *never* setup, causing subsequent tuning requests to fail. If there is time between the close and open (enough for the dvb frontend thread to be torn down), then in that case the new frontend thread is created and thus the dvb_frontend_init() function does get called. The fix is to set the flag which forces reinitialization if we did in fact call ts_bus_ctrl(). This problem has been seen on the HVR-1300, HVR-3000, and HVR-4000, and is likely occuring on other designs as well where ts_bus_ctrl() actually strobes the reset pin on the demodulator. Note that this patch should supercede any patches submitted for the 1300/3000/4000 which remove the code that removes GPIO code in cx8802_dvb_advise_acquire(), which have been circulating by users for some time now... Canonical tracking this issue in Launchpad 439163: Thanks to Jon Sayers from Hauppauge and Florent Audebert from Anevia S.A. for providing hardware to test/debug with. Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com> Cc: Jon Sayers <j.sayers@hauppauge.co.uk> Cc: Florent Audebert <florent.audebert@anevia.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
Attached is a patch which addresses a race condition in the DVB core
related to closing/reopening the DVB frontend device in quick
succession.  This is the reason that devices such as the HVR-1300,
HVR-3000, and HVR-4000 have been failing to scan properly under MythTV
and w_scan.

The gory details of the race are described in the patch.

Devin

There is a race condition exhibited when channel scanners such as w_scan and
MythTV quickly close and then reopen the frontend device node.

Under normal conditions, the behavior is as follows:

1.  Application closes the device node
2.  DVB frontend ioctl calls dvb_frontend_release which sets
    fepriv->release_jiffies
3.  DVB frontend thread *eventually* calls dvb_frontend_is_exiting() which
    compares fepriv->release_jiffies, and shuts down the thread if timeout has
    expired
4.  Thread goes away
5.  Application opens frontend device
6.  DVB frontend ioctl() calls ts_bus_ctrl(1)
7.  DVB frontend ioctl() creates new frontend thread, which calls
    dvb_frontend_init(), which has demod driver init() routine setup initial
    register state for demod chip.
8.  Tuning request is issued.

The race occurs when the application in step 5 performs the new open() call
before the frontend thread is shutdown.  In this case the ts_bus_ctrl() call
is made, which strobes the RESET pin on the demodulator, but the
dvb_frontend_init() function never gets called because the frontend thread
hasn't gone away yet.  As a result, the initial register config for the demod
is *never* setup, causing subsequent tuning requests to fail.

If there is time between the close and open (enough for the dvb frontend
thread to be torn down), then in that case the new frontend thread is created
and thus the dvb_frontend_init() function does get called.

The fix is to set the flag which forces reinitialization if we did in fact
call ts_bus_ctrl().

This problem has been seen on the HVR-1300, HVR-3000, and HVR-4000, and is
likely occuring on other designs as well where ts_bus_ctrl() actually strobes
the reset pin on the demodulator.

Note that this patch should supercede any patches submitted for the
1300/3000/4000 which remove the code that removes GPIO code in
cx8802_dvb_advise_acquire(), which have been circulating by users for some
time now...

Canonical tracking this issue in Launchpad 439163:

Thanks to Jon Sayers from Hauppauge and Florent Audebert from Anevia S.A. for
providing hardware to test/debug with.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Cc: Jon Sayers <j.sayers@hauppauge.co.uk>
Cc: Florent Audebert <florent.audebert@anevia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[media] anysee: return EOPNOTSUPP for unsupported I2C messages 2011-06-01T11:34:45+00:00 Antti Palosaari crope@iki.fi 2011-05-24T09:04:08+00:00 21d2e938d34d201276de3470587a3aa2047c77a1 Check I2C messages and return error properly. Signed-off-by: Antti Palosaari <crope@iki.fi> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
Check I2C messages and return error properly.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2011-05-27T17:14:22+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-27T17:14:22+00:00 c0880dcded3ffe77700184e9d96c110ce0094c11 * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: [media] v1.88 DM04/QQBOX Move remote to use rc_core dvb-usb-remote [media] Add missing include guard to header file [media] Inlined functions should be static [media] Remove invalid parameter description [media] cpia2: fix warning about invalid trigraph sequence [media] s5p-csis: Add missing dependency on PLAT_S5P [media] gspca/kinect: wrap gspca_debug with GSPCA_DEBUG [media] fintek-cir: new driver for Fintek LPC SuperIO CIR function [media] uvcvideo: Connect video devices to media entities [media] uvcvideo: Register subdevices for each entity [media] uvcvideo: Register a v4l2_device [media] add V4L2-PIX-FMT-SRGGB12 & friends to docbook [media] Documentation/DocBook: Rename media fops xml files [media] Media DocBook: fix validation errors [media] wl12xx: g_volatile_ctrl fix: wrong field set [media] fix kconfig dependency warning for VIDEO_TIMBERDALE [media] dm1105: GPIO handling added, I2C on GPIO added, LNB control through GPIO reworked [media] Add support for M-5MOLS 8 Mega Pixel camera ISP 
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6:
  [media] v1.88 DM04/QQBOX Move remote to use rc_core dvb-usb-remote
  [media] Add missing include guard to header file
  [media] Inlined functions should be static
  [media] Remove invalid parameter description
  [media] cpia2: fix warning about invalid trigraph sequence
  [media] s5p-csis: Add missing dependency on PLAT_S5P
  [media] gspca/kinect: wrap gspca_debug with GSPCA_DEBUG
  [media] fintek-cir: new driver for Fintek LPC SuperIO CIR function
  [media] uvcvideo: Connect video devices to media entities
  [media] uvcvideo: Register subdevices for each entity
  [media] uvcvideo: Register a v4l2_device
  [media] add V4L2-PIX-FMT-SRGGB12 & friends to docbook
  [media] Documentation/DocBook: Rename media fops xml files
  [media] Media DocBook: fix validation errors
  [media] wl12xx: g_volatile_ctrl fix: wrong field set
  [media] fix kconfig dependency warning for VIDEO_TIMBERDALE
  [media] dm1105: GPIO handling added, I2C on GPIO added, LNB control through GPIO reworked
  [media] Add support for M-5MOLS 8 Mega Pixel camera ISP
[media] v1.88 DM04/QQBOX Move remote to use rc_core dvb-usb-remote 2011-05-26T00:50:17+00:00 Malcolm Priestley tvboxspy@gmail.com 2011-05-25T21:28:29+00:00 616a4b83bd1b4ec2260a91480e211290c35348bb driver to use dvb-usb-remote. The remote(s) generates 24 bit NEC codes, lme2510 keymaps redefined. Other minor fixes fix le warning. make sure frontend is detached on firmware change. Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
driver to use dvb-usb-remote.
The remote(s) generates 24 bit NEC codes, lme2510 keymaps redefined.

Other minor fixes
fix le warning.
make sure frontend is detached on firmware change.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[media] Inlined functions should be static 2011-05-26T00:42:26+00:00 Hans Petter Selasky hselasky@c2i.net 2011-05-23T14:06:22+00:00 96c68795dc28aa3b1ade2194779c7d45320699cf Signed-off-by: Hans Petter Selasky <hselasky@c2i.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
Signed-off-by: Hans Petter Selasky <hselasky@c2i.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[media] Remove invalid parameter description 2011-05-26T00:42:23+00:00 Hans Petter Selasky hselasky@c2i.net 2011-05-23T11:28:50+00:00 2edcdfae98f2234336d5646befa6247ae03d12e8 Signed-off-by: Hans Petter Selasky <hselasky@c2i.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
Signed-off-by: Hans Petter Selasky <hselasky@c2i.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[media] dm1105: GPIO handling added, I2C on GPIO added, LNB control through GPIO reworked 2011-05-25T10:51:26+00:00 Igor M. Liplianin liplianin@me.by 2011-05-05T19:35:01+00:00 0017505de0d2888f57a9f84e8eb3963b3cd28baf Here is patch for GPIO's handling. It allows to support I2C on GPIO's and per board LNB control through GPIO's. Also incuded some support for Hendrik Skarpeid card. For those, who needs to tweak the driver, I think it is clear how to change and test GPIO's for LNB and other GPIO related stuff now. [mchehab@redhat.com: I2C_CLASS_TV_DIGITAL is deprecated. removed to avoid breaking compilation] Signed-off-by: Igor M. Liplianin <liplianin@me.by> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
Here is patch for GPIO's handling.
It allows to support I2C on GPIO's and per board LNB control through GPIO's.
Also incuded some support for Hendrik Skarpeid card.
For those, who needs to tweak the driver,
I think it is clear how to change and test GPIO's for LNB and other GPIO related stuff now.

[mchehab@redhat.com: I2C_CLASS_TV_DIGITAL is deprecated. removed to avoid breaking compilation]
Signed-off-by: Igor M. Liplianin <liplianin@me.by>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2011-05-24T04:12:49+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-24T04:12:49+00:00 df462b3dbeeaae7141f1b63cbfcc1e1bae6a85fc * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (247 commits) [media] gspca - sunplus: Fix some warnings and simplify code [media] gspca: Fix some warnings tied to 'no debug' [media] gspca: Unset debug by default [media] gspca - cpia1: Remove a bad conditional compilation instruction [media] gspca - main: Remove USB traces [media] gspca - main: Version change to 2.13 [media] gspca - stk014 / t613: Accept the index 0 in querymenu [media] gspca - kinect: Remove __devinitdata [media] gspca - cpia1: Fix some warnings [media] video/Kconfig: Fix mis-classified devices [media] support for medion dvb stick 1660:1921 [media] tm6000: fix uninitialized field, change prink to dprintk [media] cx231xx: Add support for Iconbit U100 [media] saa7134 add new TV cards [media] Use a more consistent value for RC repeat period [media] cx18: Move spinlock and vb_type initialisation into stream_init [media] tm6000: remove tm6010 sif audio start and stop [media] tm6000: remove unused exports [media] tm6000: add pts logging [media] tm6000: change from ioctl to unlocked_ioctl ... 
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (247 commits)
  [media] gspca - sunplus: Fix some warnings and simplify code
  [media] gspca: Fix some warnings tied to 'no debug'
  [media] gspca: Unset debug by default
  [media] gspca - cpia1: Remove a bad conditional compilation instruction
  [media] gspca - main: Remove USB traces
  [media] gspca - main: Version change to 2.13
  [media] gspca - stk014 / t613: Accept the index 0 in querymenu
  [media] gspca - kinect: Remove __devinitdata
  [media] gspca - cpia1: Fix some warnings
  [media] video/Kconfig: Fix mis-classified devices
  [media] support for medion dvb stick 1660:1921
  [media] tm6000: fix uninitialized field, change prink to dprintk
  [media] cx231xx: Add support for Iconbit U100
  [media] saa7134 add new TV cards
  [media] Use a more consistent value for RC repeat period
  [media] cx18: Move spinlock and vb_type initialisation into stream_init
  [media] tm6000: remove tm6010 sif audio start and stop
  [media] tm6000: remove unused exports
  [media] tm6000: add pts logging
  [media] tm6000: change from ioctl to unlocked_ioctl
  ...
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23T16:12:26+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-23T16:12:26+00:00 57d19e80f459dd845fb3cfeba8e6df8471bac142 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) b43: fix comment typo reqest -> request Haavard Skinnemoen has left Atmel cris: typo in mach-fs Makefile Kconfig: fix copy/paste-ism for dell-wmi-aio driver doc: timers-howto: fix a typo ("unsgined") perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course'). treewide: fix a few typos in comments regulator: change debug statement be consistent with the style of the rest Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations" audit: acquire creds selectively to reduce atomic op overhead rtlwifi: don't touch with treewide double semicolon removal treewide: cleanup continuations and remove logging message whitespace ath9k_hw: don't touch with treewide double semicolon removal include/linux/leds-regulator.h: fix syntax in example code tty: fix typo in descripton of tty_termios_encode_baud_rate xtensa: remove obsolete BKL kernel option from defconfig m68k: fix comment typo 'occcured' arch:Kconfig.locks Remove unused config option. treewide: remove extra semicolons ... 
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  b43: fix comment typo reqest -> request
  Haavard Skinnemoen has left Atmel
  cris: typo in mach-fs Makefile
  Kconfig: fix copy/paste-ism for dell-wmi-aio driver
  doc: timers-howto: fix a typo ("unsgined")
  perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
  md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
  treewide: fix a few typos in comments
  regulator: change debug statement be consistent with the style of the rest
  Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
  audit: acquire creds selectively to reduce atomic op overhead
  rtlwifi: don't touch with treewide double semicolon removal
  treewide: cleanup continuations and remove logging message whitespace
  ath9k_hw: don't touch with treewide double semicolon removal
  include/linux/leds-regulator.h: fix syntax in example code
  tty: fix typo in descripton of tty_termios_encode_baud_rate
  xtensa: remove obsolete BKL kernel option from defconfig
  m68k: fix comment typo 'occcured'
  arch:Kconfig.locks Remove unused config option.
  treewide: remove extra semicolons
  ...
[media] support for medion dvb stick 1660:1921 2011-05-21T10:38:55+00:00 Stéphane Elmaleh stephane.elmaleh@laposte.net 2011-05-21T10:33:38+00:00 d1402307c23cfeafce2313d936a4a990eb8783f7 [mchehab@redhat.com: The same patch were sent by Alf and by Randoslaw. I've applied the oldest version, just fixing the entry index] Cc: Patrick Boettcher <pboettcher@kernellabs.com> Tested-by: James Huk <huk256@gmail.com> Tested-by: Alf Fahland <alf-f@gmx.de> Signed-off-by: Radoslaw Warowny <radoslaww@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 
[mchehab@redhat.com: The same patch were sent by Alf and by Randoslaw.
I've applied the oldest version, just fixing the entry index]

Cc: Patrick Boettcher <pboettcher@kernellabs.com>
Tested-by: James Huk <huk256@gmail.com>
Tested-by: Alf Fahland <alf-f@gmx.de>
Signed-off-by: Radoslaw Warowny <radoslaww@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>