This patch cause oops on android mainline kernel about gadget audio_source. Androidx86 run on android mainline kernel. [ 385.104963] android_work: sent uevent USB_STATE=CONNECTED [ 385.109006] android_work: sent uevent USB_STATE=DISCONNECTED [ 385.182024] android_work: sent uevent USB_STATE=CONNECTED [ 385.184737] configfs-gadget gadget: high-speed config #1: b [ 385.184921] android_work: sent uevent USB_STATE=CONFIGURED [ 385.285268] BUG: kernel NULL pointer dereference, address: 0000000000000220 [ 385.285339] #PF: supervisor read access in kernel mode [ 385.285374] #PF: error_code(0x0000) - not-present page [ 385.285436] PGD 80000000791e6067 P4D 80000000791e6067 PUD 0 [ 385.285473] Oops: 0000 [#1] PREEMPT SMP PTI [ 385.285509] CPU: 0 PID: 5780 Comm: Binder:1383_5 Tainted: G O 5.4.0-rc6-android-x86_64+ #1 [ 385.285571] Hardware name: Insyde ONDA Tablet/ONDA Tablet, BIOS ONDA.D890HBBNR0A 03/11/2015 [ 385.285639] RIP: 0010:dma_can_mmap+0x5/0x30 [ 385.285675] Code: 74 11 e9 ae 98 b2 00 48 8b 05 9f 40 94 01 48 85 c0 75 e3 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00 <48> 8b 87 20 02 00 00 48 85 c0 74 09 48 83 78 10 00 0f 95 c0 c3 48 [ 385.285762] RSP: 0018:ffffb39443b63b78 EFLAGS: 00010246 [ 385.285797] RAX: 0000000000000001 RBX: ffffa28b91756600 RCX: 0000000000000040 [ 385.285857] RDX: ffffffffb62b2a00 RSI: 0000000000000000 RDI: 0000000000000000 [ 385.285917] RBP: ffffa28bac69f800 R08: ffffffffb63141b0 R09: ffffa28bf9a34a88 [ 385.285952] R10: ffffffffb62b2be0 R11: ffffffffb62b2bd0 R12: 0000000000000008 [ 385.286013] R13: 0000000000000000 R14: ffffa28bacd736a8 R15: ffffa28bacd736c8 [ 385.286076] FS: 0000000000000000(0000) GS:ffffa28bfb600000(0063) knlGS:00000000f5d81970 [ 385.286110] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 385.286171] CR2: 0000000000000220 CR3: 000000007b2f6000 CR4: 00000000001006f0 [ 385.286232] Call Trace: [ 385.286275] snd_pcm_hw_constraints_complete+0x3e/0x1f0 [ 385.286314] snd_pcm_open_substream+0x94/0x140 [ 385.286377] snd_pcm_open+0xf0/0x240 [ 385.286416] ? wake_up_q+0x60/0x60 [ 385.286460] snd_pcm_playback_open+0x3d/0x60 [ 385.286533] chrdev_open+0xa2/0x1c0 [ 385.286574] ? cdev_put.part.0+0x20/0x20 [ 385.286615] do_dentry_open+0x13a/0x380 [ 385.286686] path_openat+0x588/0x15d0 [ 385.286728] do_filp_open+0x91/0x100 [ 385.286769] ? __check_object_size+0x136/0x147 [ 385.286840] do_sys_open+0x184/0x280 [ 385.286880] ? handle_mm_fault+0xd7/0x1c0 [ 385.286920] do_fast_syscall_32+0x8e/0x250 [ 385.286992] entry_SYSENTER_compat+0x7c/0x8e [ 385.287302] CR2: 0000000000000220 [ 385.287391] ---[ end trace 73ffcefcbbe2b9a0 ]--- [ 385.296269] RIP: 0010:dma_can_mmap+0x5/0x30 [ 385.296337] Code: 74 11 e9 ae 98 b2 00 48 8b 05 9f 40 94 01 48 85 c0 75 e3 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00 <48> 8b 87 20 02 00 00 48 85 c0 74 09 48 83 78 10 00 0f 95 c0 c3 48 [ 385.296407] RSP: 0018:ffffb39443b63b78 EFLAGS: 00010246 [ 385.296477] RAX: 0000000000000001 RBX: ffffa28b91756600 RCX: 0000000000000040 [ 385.296516] RDX: ffffffffb62b2a00 RSI: 0000000000000000 RDI: 0000000000000000 [ 385.296584] RBP: ffffa28bac69f800 R08: ffffffffb63141b0 R09: ffffa28bf9a34a88 [ 385.296654] R10: ffffffffb62b2be0 R11: ffffffffb62b2bd0 R12: 0000000000000008 [ 385.296693] R13: 0000000000000000 R14: ffffa28bacd736a8 R15: ffffa28bacd736c8 [ 385.296761] FS: 0000000000000000(0000) GS:ffffa28bfb600000(0063) knlGS:00000000f5d81970 [ 385.296830] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 385.296867] CR2: 0000000000000220 CR3: 000000007b2f6000 CR4: 00000000001006f0 [ 385.296936] Kernel panic - not syncing: Fatal exception [ 385.296985] Kernel Offset: 0x33e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 385.305185] Rebooting in 5 seconds.. Revert it no the oops. Revert "ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_*" This reverts commit 425da159707b271dc865d7e167ac104a0e60e4af. --- sound/core/pcm_native.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 91c6ad58729f..61f6229c9124 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -220,12 +220,13 @@ static bool hw_support_mmap(struct snd_pcm_substream *substream) { if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP)) return false; - - if (substream->ops->mmap || - substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_DEV) - return true; - - return dma_can_mmap(substream->dma_buffer.dev.dev); + /* architecture supports dma_mmap_coherent()? */ +#if defined(CONFIG_MMU) || !defined(CONFIG_HAS_DMA) + if (!substream->ops->mmap && + substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) + return false; +#endif + return true; } static int constrain_mask_params(struct snd_pcm_substream *substream,