Re: [PATCH 0/7] HID: picoLCD updates
From: David Herrmann <hidden>
Date: 2012-07-31 07:26:12
Also in:
linux-input, lkml
Hi Bruno On Mon, Jul 30, 2012 at 9:36 PM, Bruno Prémont [off-list ref] wrote:
Hi, This series updates picoLCD driver: - split the driver functions into separate files which get included depending on Kconfig selection (implementation for CIR using RC_CORE will follow later) - drop private framebuffer refcounting in favor of refcounting added to fb_info some time ago - fix various bugs issues - disabled firmware version checking in probe() as it does not work anymore since commit 4ea5454203d991ec85264f64f89ca8855fce69b0 [HID: Fix race condition between driver core and ll-driver] Note: I still get weird behavior on quick unbind/bind sequences issued via sysfs (CONFIG_SMP=n system) that are triggered by framebuffer support and apparently more specifically fb_defio part of it. Unfortunately I'm out of ideas as to how to track down the problem which shows either as SLAB corruption (detected with SLUB debugging, e.g. [ 6383.521833] ======================================> [ 6383.530020] BUG kmalloc-64 (Not tainted): Object already free [ 6383.530020] ----------------------------------------------------------------------------- [ 6383.530020] [ 6383.530020] INFO: Slab 0xdde0ea20 objectsQ used@ fp=0xcef516e0 flags=0x40000080 [ 6383.530020] INFO: Object 0xcef51190 @offset@0 fp=0xcef51f50 [ 6383.530020] [ 6383.530020] Bytes b4 cef51180: cc cc cc cc d0 12 f5 ce 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ [ 6383.530020] Object cef51190: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [ 6383.530020] Object cef511a0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [ 6383.530020] Object cef511b0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [ 6383.530020] Object cef511c0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk. [ 6383.530020] Redzone cef511d0: bb bb bb bb .... [ 6383.530020] Padding cef511d8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ [ 6383.530020] Pid: 1922, comm: bash Not tainted 3.5.0-jupiter-00003-g8d858b1-dirty #2 [ 6383.530020] Call Trace: [ 6383.530020] [<c10bd3cc>] print_trailer+0x11c/0x130 [ 6383.530020] [<c10bd415>] object_err+0x35/0x40 [ 6383.530020] [<c10be809>] free_debug_processing+0x99/0x200 [ 6383.530020] [<c10bf77e>] __slab_free+0x2e/0x280 [ 6383.530020] [<c1322284>] ? hid_submit_out+0xa4/0x120 [ 6383.530020] [<c1322870>] ? __usbhid_submit_report+0xc0/0x3c0 [ 6383.530020] [<c10bfbda>] ? kfree+0xfa/0x110 [ 6383.530020] [<de932aa4>] ? picolcd_debug_out_report+0x8c4/0x8e0 [hid_picolcd] [ 6383.530020] [<c10bfbda>] kfree+0xfa/0x110 [ 6383.530020] [<c1322284>] ? hid_submit_out+0xa4/0x120 [ 6383.530020] [<c1322284>] ? hid_submit_out+0xa4/0x120 [ 6383.530020] [<c1322284>] ? hid_submit_out+0xa4/0x120 [ 6383.530020] [<c1322284>] hid_submit_out+0xa4/0x120 [ 6383.530020] [<c1322908>] __usbhid_submit_report+0x158/0x3c0 [ 6383.530020] [<c1322c2b>] usbhid_submit_report+0x1b/0x30 [ 6383.530020] [<de930789>] picolcd_fb_reset+0xb9/0x180 [hid_picolcd] [ 6383.530020] [<de930f1d>] picolcd_init_framebuffer+0x20d/0x2e0 [hid_picolcd] [ 6383.530020] [<de92fb9c>] picolcd_probe+0x3cc/0x580 [hid_picolcd] [ 6383.530020] [<c1319147>] hid_device_probe+0x67/0xf0 [ 6383.530020] [<c1282f97>] ? driver_sysfs_add+0x57/0x80 [ 6383.530020] [<c128329d>] driver_probe_device+0xbd/0x1c0 [ 6383.530020] [<c1318a1b>] ? hid_match_device+0x7b/0x90 [ 6383.530020] [<c12821e5>] driver_bind+0x75/0xd0 [ 6383.530020] [<c1282170>] ? driver_unbind+0x90/0x90 [ 6383.530020] [<c12818b7>] drv_attr_store+0x27/0x30 [ 6383.530020] [<c1114aec>] sysfs_write_file+0xac/0xf0 [ 6383.530020] [<c10c794c>] vfs_write+0x9c/0x130 [ 6383.530020] [<c10d4a1f>] ? sys_dup3+0x11f/0x160 [ 6383.530020] [<c1114a40>] ? sysfs_poll+0x90/0x90 [ 6383.530020] [<c10c7bbd>] sys_write+0x3d/0x70 [ 6383.530020] [<c13f2557>] sysenter_do_call+0x12/0x26 [ 6383.530020] FIX kmalloc-64: Object at 0xcef51190 not freed or worse spontaneous reboot of the system without any trace on netconsole or serial console. echo $devid > bind; echo $devid > unbind or echo $devid > bind; echo $devid > unbind; sleep 0.2; echo $devid > bind; echo $devid > unbind is sufficient to trigger the above issue while waiting a few seconds between bind and unbind shows no sign of trouble. Suggestions as to how to debug this and fix it are welcome!
This is not directly related to this patchset, but did you fix the locking issue with hid-core? It is still on my todo-list but I haven't gotten around fixing it, yet. However, I plan on fixing it this summer, but if picolcd does not require it, it's probably not worth the work. Regards David