Re: [PATCH 1/2] drivers: i2c: qup: Fix broken dma when CONFIG_DEBUG_SG is enabled

[Andy Gross]

On Mon, May 02, 2016 at 10:53:56AM +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.
> 
> Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx>

Looks fine.

Reviewed-by: Andy Gross <andy.gross@xxxxxxxxxx>