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[ Upstream commit f030e419501cb95e961e9ed35c493b5d46a04eca ] Following kernel panic is seen during DMA driver unload->load sequence ========================================================================== Unable to handle kernel paging request at virtual address ffffff8001198880 Internal error: Oops: 86000007 [#1] PREEMPT SMP CPU: 0 PID: 5907 Comm: HwBinder:4123_1 Tainted: G C 4.9.128-tegra-g065839f Hardware name: galen (DT) task: ffffffc3590d1a80 task.stack: ffffffc3d0678000 PC is at 0xffffff8001198880 LR is at of_dma_request_slave_channel+0xd8/0x1f8 pc : [<ffffff8001198880>] lr : [<ffffff8008746f30>] pstate: 60400045 sp : ffffffc3d067b710 x29: ffffffc3d067b710 x28: 000000000000002f x27: ffffff800949e000 x26: ffffff800949e750 x25: ffffff800949e000 x24: ffffffbefe817d84 x23: ffffff8009f77cb0 x22: 0000000000000028 x21: ffffffc3ffda49c8 x20: 0000000000000029 x19: 0000000000000001 x18: ffffffffffffffff x17: 0000000000000000 x16: ffffff80082b66a0 x15: ffffff8009e78250 x14: 000000000000000a x13: 0000000000000038 x12: 0101010101010101 x11: 0000000000000030 x10: 0101010101010101 x9 : fffffffffffffffc x8 : 7f7f7f7f7f7f7f7f x7 : 62ff726b6b64622c x6 : 0000000000008064 x5 : 6400000000000000 x4 : ffffffbefe817c44 x3 : ffffffc3ffda3e08 x2 : ffffff8001198880 x1 : ffffffc3d48323c0 x0 : ffffffc3d067b788 Process HwBinder:4123_1 (pid: 5907, stack limit = 0xffffffc3d0678028) Call trace: [<ffffff8001198880>] 0xffffff8001198880 [<ffffff80087459f8>] dma_request_chan+0x50/0x1f0 [<ffffff8008745bc0>] dma_request_slave_channel+0x28/0x40 [<ffffff8001552c44>] tegra_alt_pcm_open+0x114/0x170 [<ffffff8008d65fa4>] soc_pcm_open+0x10c/0x878 [<ffffff8008d18618>] snd_pcm_open_substream+0xc0/0x170 [<ffffff8008d1878c>] snd_pcm_open+0xc4/0x240 [<ffffff8008d189e0>] snd_pcm_playback_open+0x58/0x80 [<ffffff8008cfc6d4>] snd_open+0xb4/0x178 [<ffffff8008250628>] chrdev_open+0xb8/0x1d0 [<ffffff8008246fdc>] do_dentry_open+0x214/0x318 [<ffffff80082485d0>] vfs_open+0x58/0x88 [<ffffff800825bce0>] do_last+0x450/0xde0 [<ffffff800825c718>] path_openat+0xa8/0x368 [<ffffff800825dd84>] do_filp_open+0x8c/0x110 [<ffffff8008248a74>] do_sys_open+0x164/0x220 [<ffffff80082b66dc>] compat_SyS_openat+0x3c/0x50 [<ffffff8008083040>] el0_svc_naked+0x34/0x38 ---[ end trace 67e6d544e65b5145 ]--- Kernel panic - not syncing: Fatal exception ========================================================================== In device probe(), of_dma_controller_register() registers DMA controller. But when driver is removed, this is not freed. During driver reload this results in data abort and kernel panic. Add of_dma_controller_free() in driver remove path to fix the issue. Fixes: f46b195799b5 ("dmaengine: tegra-adma: Add support for Tegra210 ADMA") Signed-off-by: Sameer Pujar <spujar@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.