[PATCH V2 1/2] drivers: i2c: qup: Fix broken dma when CONFIG_DEBUG_SG is enabled
From: Wolfram Sang <hidden>
Date: 2016-05-13 11:47:23
Also in:
linux-arm-msm, linux-devicetree, linux-i2c, lkml
On Fri, May 06, 2016 at 05:01:13PM +0530, Sricharan R wrote:
With CONFIG_DEBUG_SG is enabled and when dma mode is used, below dump is seen, ------------[ cut here ]------------ kernel BUG at include/linux/scatterlist.h:140! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-00459-g9f087b9-dirty #7 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) task: ffffffc036868000 ti: ffffffc036870000 task.ti: ffffffc036870000 PC is at qup_sg_set_buf.isra.13+0x138/0x154 LR is at qup_sg_set_buf.isra.13+0x50/0x154 pc : [<ffffffc0005a0ed8>] lr : [<ffffffc0005a0df0>] pstate: 60000145 sp : ffffffc0368735c0 x29: ffffffc0368735c0 x28: ffffffc036873752 x27: ffffffc035233018 x26: ffffffc000c4e000 x25: 0000000000000000 x24: 0000000000000004 x23: 0000000000000000 x22: ffffffc035233668 x21: ffffff80004e3000 x20: ffffffc0352e0018 x19: 0000004000000000 x18: 0000000000000028 x17: 0000000000000004 x16: ffffffc0017a39c8 x15: 0000000000001cdf x14: ffffffc0019929d8 x13: ffffffc0352e0018 x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000000001 x9 : ffffffc0012b2d70 x8 : ffffff80004e3000 x7 : 0000000000000018 x6 : 0000000030000000 x5 : ffffffc00199f018 x4 : ffffffc035233018 x3 : 0000000000000004 x2 : 00000000c0000000 x1 : 0000000000000003 x0 : 0000000000000000 Process swapper/0 (pid: 1, stack limit = 0xffffffc036870020) Stack: (0xffffffc0368735c0 to 0xffffffc036874000) Change allocation of sg buffers from dma_coherent memory to kzalloc to fix the issue.
This description describes what you do. But not why it is the correct solution to the OOPS. The OOPS neither describes it. Please add some more explanation.
Signed-off-by: Sricharan R <redacted> Reviewed-by: Andy Gross <redacted>
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