* Re: backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 [not found] <20060921121952.GA16927@aepfle.de> @ 2006-09-21 19:37 ` Andrew Morton 2006-09-21 21:56 ` Michael Hanselmann 0 siblings, 1 reply; 5+ messages in thread From: Andrew Morton @ 2006-09-21 19:37 UTC (permalink / raw) To: Olaf Hering Cc: linux-fbdev-devel, Daniel R Thompson, Michael Hanselmann, linux-kernel, Smirl, Antonino A. Daplas, Jon On Thu, 21 Sep 2006 14:19:52 +0200 Olaf Hering <olaf@aepfle.de> wrote: > The bl_curve code has some room for improvement. > > ... > <6>Monitor sense value = 0x60b > <6>using video mode 13 and color mode 0. > <4>Console: switching to colour frame buffer device 104x39 > <6>fb0: valkyrie frame buffer device > ... > > inst-sys:~ # cat /proc/fb > 0 valkyrie > inst-sys:~ # l /sys/class/graphics/fb0/ > total 0 > drwxr-xr-x 2 root root 0 Sep 21 11:54 ./ > drwxr-xr-x 4 root root 0 Sep 21 11:53 ../ > -rw-r--r-- 1 root root 4096 Sep 21 12:15 bits_per_pixel > -rw-r--r-- 1 root root 4096 Sep 21 12:15 bl_curve > -rw-r--r-- 1 root root 4096 Sep 21 12:15 blank > -rw-r--r-- 1 root root 4096 Sep 21 12:15 console > -rw-r--r-- 1 root root 4096 Sep 21 12:15 cursor > -r--r--r-- 1 root root 4096 Sep 21 12:15 dev > -rw-r--r-- 1 root root 4096 Sep 21 12:15 mode > -rw-r--r-- 1 root root 4096 Sep 21 12:15 modes > -r--r--r-- 1 root root 4096 Sep 21 12:15 name > -rw-r--r-- 1 root root 4096 Sep 21 12:15 pan > -rw-r--r-- 1 root root 4096 Sep 21 12:15 rotate > -rw-r--r-- 1 root root 4096 Sep 21 12:15 state > -r--r--r-- 1 root root 4096 Sep 21 12:15 stride > lrwxrwxrwx 1 root root 0 Sep 21 12:15 subsystem -> ../../../class/graphics/ > --w------- 1 root root 4096 Sep 21 12:15 uevent > -rw-r--r-- 1 root root 4096 Sep 21 12:15 virtual_size > inst-sys:~ # head /sys/class/graphics/fb0/* > ==> /sys/class/graphics/fb0/bits_per_pixel <== > 8 > > ==> /sys/class/graphics/fb0/bl_curve <== > Segmentation fault > inst-sys:~ # dmesg > valkyriefb: vmode 13 does not support cmode 1. > Unable to handle kernel paging request for data at address 0x00000000 > Faulting instruction address: 0xc02c7bd8 > Oops: Kernel access of bad area, sig: 11 [#1] > > Modules linked in: tulip mesh cpufreq_ondemand loop nfs nfs_acl lockd sunrpc sg st sd_mod sr_mod scsi_mod ide_cd cdrom > NIP: C02C7BD8 LR: C0170EBC CTR: C0170E90 > REGS: c4209db0 TRAP: 0300 Not tainted (2.6.18-rc7-git1-2-default) > MSR: 00009032 <EE,ME,IR,DR> CR: 28042488 XER: 00000000 > DAR: 00000000, DSISR: 22000000 > TASK = c7fc8190[2853] 'head' THREAD: c4208000 > GPR00: C4209E6C C4209E60 C7FC8190 C0B77614 C41D5000 C41D5000 00000000 00008000 > GPR08: 00000000 C0B77618 00000000 00000000 00000000 100200C8 10020000 00000001 > GPR16: 10006D08 7FDF9B3C 100A0000 10080000 00000003 7FDF9CAB C4209F20 C2FCDC78 > GPR24: C038BC14 C01EF568 7FDF7858 C41D5000 C0B77614 C0B77400 C7FC8190 C0B77614 > NIP [C02C7BD8] __mutex_lock_slowpath+0x2c/0xa4 > LR [C0170EBC] show_bl_curve+0x2c/0xa0 > Call Trace: > [C4209E60] [C02C7A54] mutex_lock+0x18/0x5c (unreliable) > [C4209E80] [C0170EBC] show_bl_curve+0x2c/0xa0 > [C4209EB0] [C01EF594] class_device_attr_show+0x2c/0x44 > [C4209EC0] [C00CC3BC] sysfs_read_file+0xb8/0x204 > [C4209EF0] [C0083FE4] vfs_read+0xec/0x1c8 > [C4209F10] [C0084444] sys_read+0x4c/0x8c > [C4209F40] [C00125F8] ret_from_syscall+0x0/0x40 > --- Exception: c01 at 0xff589f8 > LR = 0x100045e0 > Instruction dump: > 4e800020 9421ffe0 7c0802a6 39230004 bfc10018 7c7f1b78 7c5e1378 90010024 > 3801000c 9121000c 81690004 90090004 <900b0000> 91610010 90410014 3800ffff > cc's added. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 2006-09-21 19:37 ` backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 Andrew Morton @ 2006-09-21 21:56 ` Michael Hanselmann 2006-09-22 11:26 ` Olaf Hering 0 siblings, 1 reply; 5+ messages in thread From: Michael Hanselmann @ 2006-09-21 21:56 UTC (permalink / raw) To: olaf Cc: linux-kernel, linux-fbdev-devel, Antonino A. Daplas, Daniel R Thompson, Jon Smirl, akpm On Thu, Sep 21, 2006 at 12:37:42PM -0700, Andrew Morton wrote: > On Thu, 21 Sep 2006 14:19:52 +0200 > Olaf Hering <olaf@aepfle.de> wrote: > > The bl_curve code has some room for improvement. Agreed. > > inst-sys:~ # dmesg > > valkyriefb: vmode 13 does not support cmode 1. > > Unable to handle kernel paging request for data at address 0x00000000 > > Faulting instruction address: 0xc02c7bd8 Seems like not all drivers use the framebuffer_alloc() function and won't have an initialized mutex. But those don't have a backlight, anyway. What about the patch below? Does it work for you? Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch> --- diff -Nrup --exclude-from linux-exclude-from linux-2.6.18.orig/drivers/video/fbsysfs.c linux-2.6.18/drivers/video/fbsysfs.c --- linux-2.6.18.orig/drivers/video/fbsysfs.c 2006-09-21 23:40:06.000000000 +0200 +++ linux-2.6.18/drivers/video/fbsysfs.c 2006-09-21 23:50:00.000000000 +0200 @@ -397,6 +397,12 @@ static ssize_t store_bl_curve(struct cla u8 tmp_curve[FB_BACKLIGHT_LEVELS]; unsigned int i; + /* Some drivers don't use framebuffer_alloc(), but those also + * don't have backlights. + */ + if (!fb_info || !fb_info->bl_dev) + return -ENODEV; + if (count != (FB_BACKLIGHT_LEVELS / 8 * 24)) return -EINVAL; @@ -430,6 +436,12 @@ static ssize_t show_bl_curve(struct clas ssize_t len = 0; unsigned int i; + /* Some drivers don't use framebuffer_alloc(), but those also + * don't have backlights. + */ + if (!fb_info || !fb_info->bl_dev) + return -ENODEV; + mutex_lock(&fb_info->bl_mutex); for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8) len += snprintf(&buf[len], PAGE_SIZE, ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 2006-09-21 21:56 ` Michael Hanselmann @ 2006-09-22 11:26 ` Olaf Hering 2006-09-22 23:02 ` Andrew Morton 0 siblings, 1 reply; 5+ messages in thread From: Olaf Hering @ 2006-09-22 11:26 UTC (permalink / raw) To: Michael Hanselmann Cc: linux-kernel, linux-fbdev-devel, Antonino A. Daplas, Daniel R Thompson, Jon Smirl, akpm On Thu, Sep 21, Michael Hanselmann wrote: > What about the patch below? Does it work for you? Appears to work. tangerine:~ # head /sys/class/graphics/fb0/* ==> /sys/class/graphics/fb0/bits_per_pixel <== 8 ==> /sys/class/graphics/fb0/bl_curve <== head: error reading `/sys/class/graphics/fb0/bl_curve': No such device ==> /sys/class/graphics/fb0/blank <== ==> /sys/class/graphics/fb0/console <== ==> /sys/class/graphics/fb0/cursor <== ==> /sys/class/graphics/fb0/dev <== 29:0 ==> /sys/class/graphics/fb0/mode <== ==> /sys/class/graphics/fb0/modes <== U:832x624p-74 ==> /sys/class/graphics/fb0/name <== valkyrie ==> /sys/class/graphics/fb0/pan <== 0,0 ==> /sys/class/graphics/fb0/rotate <== 0 ==> /sys/class/graphics/fb0/state <== 0 ==> /sys/class/graphics/fb0/stride <== 832 ==> /sys/class/graphics/fb0/subsystem <== head: error reading `/sys/class/graphics/fb0/subsystem': Is a directory head: cannot open `/sys/class/graphics/fb0/uevent' for reading: Permission denied ==> /sys/class/graphics/fb0/virtual_size <== 832,624 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 2006-09-22 11:26 ` Olaf Hering @ 2006-09-22 23:02 ` Andrew Morton 2006-09-22 23:07 ` Michael Hanselmann 0 siblings, 1 reply; 5+ messages in thread From: Andrew Morton @ 2006-09-22 23:02 UTC (permalink / raw) To: Olaf Hering Cc: linux-fbdev-devel, Daniel R Thompson, Michael Hanselmann, linux-kernel, Jon Smirl, Antonino A. Daplas On Fri, 22 Sep 2006 13:26:22 +0200 Olaf Hering <olaf@aepfle.de> wrote: > On Thu, Sep 21, Michael Hanselmann wrote: > > > What about the patch below? Does it work for you? > > Appears to work. > > tangerine:~ # head /sys/class/graphics/fb0/* > ==> /sys/class/graphics/fb0/bits_per_pixel <== > 8 > > ==> /sys/class/graphics/fb0/bl_curve <== > head: error reading `/sys/class/graphics/fb0/bl_curve': No such device > > ==> /sys/class/graphics/fb0/blank <== > > ==> /sys/class/graphics/fb0/console <== > > ==> /sys/class/graphics/fb0/cursor <== > > ==> /sys/class/graphics/fb0/dev <== > 29:0 > > ==> /sys/class/graphics/fb0/mode <== > > ==> /sys/class/graphics/fb0/modes <== > U:832x624p-74 > > ==> /sys/class/graphics/fb0/name <== > valkyrie > > ==> /sys/class/graphics/fb0/pan <== > 0,0 > > ==> /sys/class/graphics/fb0/rotate <== > 0 > > ==> /sys/class/graphics/fb0/state <== > 0 > > ==> /sys/class/graphics/fb0/stride <== > 832 > > ==> /sys/class/graphics/fb0/subsystem <== > head: error reading `/sys/class/graphics/fb0/subsystem': Is a directory > head: cannot open `/sys/class/graphics/fb0/uevent' for reading: Permission denied > > ==> /sys/class/graphics/fb0/virtual_size <== > 832,624 Still looks like a bit of a mess, but I assume that's expected. Michael, I take it that patch was final? ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 2006-09-22 23:02 ` Andrew Morton @ 2006-09-22 23:07 ` Michael Hanselmann 0 siblings, 0 replies; 5+ messages in thread From: Michael Hanselmann @ 2006-09-22 23:07 UTC (permalink / raw) To: Andrew Morton Cc: Olaf Hering, linux-kernel, linux-fbdev-devel, Antonino A. Daplas, Daniel R Thompson, Jon Smirl On Fri, Sep 22, 2006 at 04:02:55PM -0700, Andrew Morton wrote: > Still looks like a bit of a mess, but I assume that's expected. > Michael, I take it that patch was final? For now, yes. Thanks for adding it to -mm. ^ permalink raw reply [flat|nested] 5+ messages in thread
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[not found] <20060921121952.GA16927@aepfle.de>
2006-09-21 19:37 ` backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 Andrew Morton
2006-09-21 21:56 ` Michael Hanselmann
2006-09-22 11:26 ` Olaf Hering
2006-09-22 23:02 ` Andrew Morton
2006-09-22 23:07 ` Michael Hanselmann
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