Re: [PATCH v2] mmc: dw_mmc: Fix PIO mode with support of highmem

Chris Ball
2012-02-11T21:31:05Z

Hi,

On Thu, Feb 09 2012, Will Newton wrote:
> On Thu, Feb 9, 2012 at 5:32 AM, Seungwon Jeon <tgih.jun@samsung.com> wrote:
>> Current PIO mode makes a kernel crash with CONFIG_HIGHMEM.
>> Highmem pages have a NULL from sg_virt(sg).
>> This patch fixes the following problem.
>>
>> Unable to handle kernel NULL pointer dereference at virtual address 00000000
>> pgd = c0004000
>> [00000000] *pgd=00000000
>> Internal error: Oops: 817 [#1] PREEMPT SMP
>> Modules linked in:
>> CPU: 0    Not tainted  (3.0.15-01423-gdbf465f #589)
>> PC is at dw_mci_pull_data32+0x4c/0x9c
>> LR is at dw_mci_read_data_pio+0x54/0x1f0
>> pc : [<c0358824>]    lr : [<c035988c>]    psr: 20000193
>> sp : c0619d48  ip : c0619d70  fp : c0619d6c
>> r10: 00000000  r9 : 00000002  r8 : 00001000
>> r7 : 00000200  r6 : 00000000  r5 : e1dd3100  r4 : 00000000
>> r3 : 65622023  r2 : 0000007f  r1 : eeb96000  r0 : e1dd3100
>> Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment
>> kernel
>> Control: 10c5387d  Table: 61e2004a  DAC: 00000015
>> Process swapper (pid: 0, stack limit = 0xc06182f0)
>> Stack: (0xc0619d48 to 0xc061a000)
>> 9d40:                   e1dd3100 e1a4f000 00000000 e1dd3100 e1a4f000 00000200
>> 9d60: c0619da4 c0619d70 c035988c c03587e4 c0619d9c e18158f4 e1dd3100 e1dd3100
>> 9d80: 00000020 00000000 00000000 00000020 c06e8a84 00000000 c0619e04 c0619da8
>> 9da0: c0359b24 c0359844 e18158f4 e1dd3164 e1dd3168 e1dd3150 3d02fc79 e1dd3154
>> 9dc0: e1dd3178 00000000 00000020 00000000 e1dd3150 00000000 c10dd7e8 e1a84900
>> 9de0: c061e7cc 00000000 00000000 0000008d c06e8a84 c061e780 c0619e4c c0619e08
>> 9e00: c00c4738 c0359a34 3d02fc79 00000000 c0619e4c c05a1698 c05a1670 c05a165c
>> 9e20: c04de8b0 c061e780 c061e7cc e1a84900 ffffed68 0000008d c0618000 00000000
>> 9e40: c0619e6c c0619e50 c00c48b4 c00c46c8 c061e780 c00423ac c061e7cc ffffed68
>> 9e60: c0619e8c c0619e70 c00c7358 c00c487c 0000008d ffffee38 c0618000 ffffed68
>> 9e80: c0619ea4 c0619e90 c00c4258 c00c72b0 c00423ac ffffee38 c0619ecc c0619ea8
>> 9ea0: c004241c c00c4234 ffffffff f8810000 0000006d 00000002 00000001 7fffffff
>> 9ec0: c0619f44 c0619ed0 c0048bc0 c00423c4 220ae7a9 00000000 386f0d30 0005d3a4
>> 9ee0: c00423ac c10dd0b8 c06f2cd8 c0618000 c0594778 c003a674 7fffffff c0619f44
>> 9f00: 386f0d30 c0619f18 c00a6f94 c005be3c 80000013 ffffffff 386f0d30 0005d3a4
>> 9f20: 386f0d30 0005d2d1 c10dd0a8 c10dd0b8 c06f2cd8 c0618000 c0619f74 c0619f48
>> 9f40: c0345858 c005be00 c00a2440 c0618000 c0618000 c00410d8 c06c1944 c00410fc
>> 9f60: c0594778 c003a674 c0619f9c c0619f78 c004a7e8 c03457b4 c0618000 c06c18f8
>> 9f80: 00000000 c0039c70 c06c18d4 c003a674 c0619fb4 c0619fa0 c04ceafc c004a714
>> 9fa0: c06287b4 c06c18f8 c0619ff4 c0619fb8 c0008b68 c04cea68 c0008578 00000000
>> 9fc0: 00000000 c003a674 00000000 10c5387d c0628658 c003aa78 c062f1c4 4000406a
>> 9fe0: 413fc090 00000000 00000000 c0619ff8 40008044 c0008858 00000000 00000000
>> Backtrace:
>> [<c03587d8>] (dw_mci_pull_data32+0x0/0x9c) from [<c035988c>]
>> (dw_mci_read_data_pio+0x54/0x1f0)
>>  r6:00000200 r5:e1a4f000 r4:e1dd3100
>>  [<c0359838>] (dw_mci_read_data_pio+0x0/0x1f0) from [<c0359b24>]
>> (dw_mci_interrupt+0xfc/0x4a4)
>> [<c0359a28>] (dw_mci_interrupt+0x0/0x4a4) from [<c00c4738>]
>> (handle_irq_event_percpu+0x7c/0x1b4)
>> [<c00c46bc>] (handle_irq_event_percpu+0x0/0x1b4) from [<c00c48b4>]
>> (handle_irq_event+0x44/0x64)
>> [<c00c4870>] (handle_irq_event+0x0/0x64) from [<c00c7358>]
>> (handle_fasteoi_irq+0xb4/0x124)
>>  r7:ffffed68 r6:c061e7cc r5:c00423ac r4:c061e780
>>  [<c00c72a4>] (handle_fasteoi_irq+0x0/0x124) from [<c00c4258>]
>> (generic_handle_irq+0x30/0x38)
>>  r7:ffffed68 r6:c0618000 r5:ffffee38 r4:0000008d
>>  [<c00c4228>] (generic_handle_irq+0x0/0x38) from [<c004241c>]
>> (asm_do_IRQ+0x64/0xe0)
>>  r5:ffffee38 r4:c00423ac
>>  [<c00423b8>] (asm_do_IRQ+0x0/0xe0) from [<c0048bc0>] (__irq_svc+0x80/0x14c)
>> Exception stack(0xc0619ed0 to 0xc0619f18)
>>
>> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
>
> This patch looks ok to me.
>
> Acked-by: Will Newton <will.newton@imgtec.com>

Thanks, pushed to mmc-next for 3.3 with a stable@ tag added.

- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child