On 2014년 11월 21일 08:12, Gustavo Padovan wrote: > 2014-11-13 Inki Dae <inki.dae@xxxxxxxxxxx>: > >> This patch fixes null pointer dereference issue incurred >> when ipp driver is enabled and Exynos drm driver is closed. >> >> Non kms driver should register its own sub driver to setup necessary >> resources, which is done by load(). So null pointer dereference >> occurs when ipp driver is enabled and Exynos drm driver is closed >> because ipp core device is registered after component_master_add_with_match >> call. >> >> This patch makes exynos_drm_device_subdrv_probe() to be called after all non >> kms drivers are registered. > > This patch is breaking exynos initialization, exynos_drm_device_subdrv_probe() > needs the drvdata but it is still NULL at this point which make the whole > exynos init fails. The drvdata is only set in exynos_drm_load() so we need > call exynos_drm_device_subdrv_probe() after that. There might be my missing point but with this patch, exynos_drm_device_subdrv_probe() will be called after exynos_drm_load() call because all kms drivers are probed before component_master_add_with_match call so exynos_drm_load() must be called by component_master_add_with_match function before exynos_drm_device_subdrv_probe call. So could you show me the error messages you faced with? There might be a corner case I missed. > > Do you have the crash output for this? What is the issue you are fixing? Ok, below is the error messages, # modetest [ 5.653291] ------------[ cut here ]------------ [ 5.656469] WARNING: CPU: 2 PID: 1404 at kernel/locking/mutex.c:511 __mutex_lock_slowpath+0x3d4/0x3d8() [ 5.665816] DEBUG_LOCKS_WARN_ON(l->magic != l) [ 5.670069] Modules linked in: [ 5.673286] CPU: 2 PID: 1404 Comm: modetest Not tainted 3.18.0-rc3-146775-gbcfef97 #1149 [ 5.681389] [<c0014400>] (unwind_backtrace) from [<c0011570>] (show_stack+0x10/0x14) [ 5.689090] [<c0011570>] (show_stack) from [<c0474060>] (dump_stack+0x84/0xc4) [ 5.696304] [<c0474060>] (dump_stack) from [<c0021918>] (warn_slowpath_common+0x6c/0x88) [ 5.704364] [<c0021918>] (warn_slowpath_common) from [<c0021964>] (warn_slowpath_fmt+0x30/0x40) [ 5.713047] [<c0021964>] (warn_slowpath_fmt) from [<c0477a4c>] (__mutex_lock_slowpath+0x3d4/0x3d8) [ 5.721984] [<c0477a4c>] (__mutex_lock_slowpath) from [<c0477a5c>] (mutex_lock+0xc/0x24) [ 5.730069] [<c0477a5c>] (mutex_lock) from [<c028e6fc>] (ipp_subdrv_close+0x4c/0x13c) [ 5.737881] [<c028e6fc>] (ipp_subdrv_close) from [<c027a51c>] (exynos_drm_subdrv_close+0x3c/0x4c) [ 5.746731] [<c027a51c>] (exynos_drm_subdrv_close) from [<c025eadc>] (drm_release+0x94/0x4c8) [ 5.755228] [<c025eadc>] (drm_release) from [<c00cbdd4>] (__fput+0x80/0x1c8) [ 5.762268] [<c00cbdd4>] (__fput) from [<c0037840>] (task_work_run+0xac/0xe4) [ 5.769382] [<c0037840>] (task_work_run) from [<c00110f8>] (do_work_pending+0x94/0xb4) [ 5.777275] [<c00110f8>] (do_work_pending) from [<c000e6e0>] (work_pending+0xc/0x20) [ 5.784994] ---[ end trace bb48a41ae89d1f25 ]--- [ 5.789598] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 5.797664] pgd = ee3b8000 [ 5.800354] [00000000] *pgd=6e366831, *pte=00000000, *ppte=00000000 [ 5.806610] Internal error: Oops: 817 [#1] PREEMPT SMP ARM [ 5.812074] Modules linked in: [ 5.815117] CPU: 2 PID: 1404 Comm: modetest Tainted: G W 3.18.0-rc3-146775-gbcfef97 #1149 [ 5.824314] task: eea90800 ti: ee33c000 task.ti: ee33c000 [ 5.829704] PC is at __mutex_lock_slowpath+0xf4/0x3d8 [ 5.834730] LR is at __mutex_lock_slowpath+0xdc/0x3d8 [ 5.839765] pc : [<c047776c>] lr : [<c0477754>] psr: 80000093 [ 5.839765] sp : ee33de88 ip : ee33de98 fp : c06cb814 [ 5.851220] r10: ee0f5854 r9 : c0700784 r8 : eea90800 [ 5.856429] r7 : ee33c008 r6 : 60000013 r5 : ee0f5844 r4 : ee0f5840 [ 5.862938] r3 : 00000000 r2 : 00000000 r1 : ee33de88 r0 : ee0f5840 [ 5.869451] Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user [ 5.876654] Control: 10c5387d Table: 6e3b804a DAC: 00000015 [ 5.882383] Process modetest (pid: 1404, stack limit = 0xee33c240) [ 5.888544] Stack: (0xee33de88 to 0xee33e000) [ 5.892888] de80: ee0f5854 00000000 11111111 ee33de88 0001d030 ee0f5840 [ 5.901048] dea0: c06b1d94 ee0f5810 c0705e4c ee0eeb00 00000000 ee0f5840 ee0f5810 c0477a5c [ 5.909207] dec0: eeb4a510 c028e6fc ee14a434 eeb4a510 c06b2fe4 ee14a400 ee33c000 eeb4a510 [ 5.917366] dee0: c06b1d94 ee0eeb00 ee14a400 ee14a434 00000008 ee0eea08 00000000 c027a51c [ 5.925525] df00: c0705e4c ee0eeb00 ee0eea00 ee14a400 ee14a434 c025eadc ee0eea08 00000001 [ 5.933684] df20: eebce000 00000000 00000000 00000000 00000021 ee0eea00 ee3354e0 00000000 [ 5.941843] df40: ee32a250 ee711428 00000008 ee0eea08 00000000 c00cbdd4 00000000 00000000 [ 5.950002] df60: eea90b4c 00000000 c06ca604 eea90800 c000e824 ee33c000 00000000 c0037840 [ 5.958161] df80: ee33c018 c000e824 ee33dfb0 ee33c000 c000e824 c00110f8 00000003 00000001 [ 5.966320] dfa0: beff0a4c 00000006 c000e824 c000e6e0 00000000 0001d000 00000003 0001d000 [ 5.974479] dfc0: 00000003 00000001 beff0a4c 00000006 00000000 00000000 00000000 00000000 [ 5.982639] dfe0: 00000000 beff09a4 b6f74257 b6eef626 40000030 00000003 00000000 00000000 [ 5.990807] [<c047776c>] (__mutex_lock_slowpath) from [<c0477a5c>] (mutex_lock+0xc/0x24) [ 5.998883] [<c0477a5c>] (mutex_lock) from [<c028e6fc>] (ipp_subdrv_close+0x4c/0x13c) [ 6.006693] [<c028e6fc>] (ipp_subdrv_close) from [<c027a51c>] (exynos_drm_subdrv_close+0x3c/0x4c) [ 6.015546] [<c027a51c>] (exynos_drm_subdrv_close) from [<c025eadc>] (drm_release+0x94/0x4c8) [ 6.024047] [<c025eadc>] (drm_release) from [<c00cbdd4>] (__fput+0x80/0x1c8) [ 6.031082] [<c00cbdd4>] (__fput) from [<c0037840>] (task_work_run+0xac/0xe4) [ 6.038200] [<c0037840>] (task_work_run) from [<c00110f8>] (do_work_pending+0x94/0xb4) [ 6.046094] [<c00110f8>] (do_work_pending) from [<c000e6e0>] (work_pending+0xc/0x20) [ 6.053816] Code: e284a014 e584d018 e58da000 e58d3004 (e583d000) [ 6.059892] ---[ end trace bb48a41ae89d1f26 ]--- Thanks, Inki Dae > Usually you should add this kind of information to you commit message, it > helps us understand what you are fixing, specially in cases when a regression > is introduced, like this patch for example > > Gustavo > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line 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