> Subject: usb: phy: phy-mxs-usb: suspend to RAM causes NULL pointer
> dereference
>
> Hi,
>
> triggering suspend to RAM via sysfs on a i.MX28 causes a NULL pointer
> dereference. This regression seems to be introduced with commit
> efdbd3a5d6e
> ("usb: phy: mxs: do not set PWD.RXPWD1PT1 for low speed connection"):
>
> root@duckbill:/sys/power# echo mem > state
> [ 83.677575] PM: Syncing filesystems ... done.
> [ 83.872011] Freezing user space processes ... (elapsed 0.006 seconds) done.
> [ 83.886817] Freezing remaining freezable tasks ... (elapsed 0.003 seconds)
> done.
> [ 83.909215] Unable to handle kernel NULL pointer dereference at virtual
> address 0000017c
> [ 83.917520] pgd = c6d88000
> [ 83.920277] [0000017c] *pgd=46ed9831, *pte=00000000, *ppte=00000000
> [ 83.926795] Internal error: Oops: 17 [#1] ARM
> [ 83.931191] Modules linked in:
> [ 83.934306] CPU: 0 PID: 435 Comm: bash Not tainted
> 4.0.0-rc4-next-20150320-gb8f4f66-dirty #163
> [ 83.942940] Hardware name: Freescale MXS (Device Tree)
> [ 83.948102] task: c4954d00 ti: c6d20000 task.ti: c6d20000
> [ 83.953544] PC is at regmap_read+0x10/0x5c
> [ 83.957695] LR is at mxs_phy_get_vbus_status+0x40/0x58
> [ 83.962865] pc : [<c0350a10>] lr : [<c03d8ac4>] psr: 60000013
> [ 83.962865] sp : c6d21d20 ip : 00800000 fp : 00000002
> [ 83.974368] r10: c0340180 r9 : c07c15b0 r8 : 00000002
> [ 83.979615] r7 : c06c6ad4 r6 : 00000000 r5 : 000001c0 r4 : 00000000
> [ 83.986166] r3 : 00000000 r2 : c6d21d34 r1 : 000001c0 r0 : 000001c0
> [ 83.992718] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment
> user
> [ 83.999876] Control: 0005317f Table: 46d88000 DAC: 00000015
> [ 84.005644] Process bash (pid: 435, stack limit = 0xc6d20190)
> [ 84.011413] Stack: (0xc6d21d20 to 0xc6d22000)
> [ 84.015813] 1d20: c7833f10 00000001 00000000 c03d8ac4 00000002 c00601c8
> 00001074 c03d8ca4
> [ 84.024030] 1d40: c0537268 60000013 c7a6bc10 c7aea010 c7a6bc10 00001074
> c06c6ad4 c03d924c
> [ 84.032245] 1d60: c7aea010 c03d93dc c7a6bc10 c0fcf05c c07e165c c03401ac
> c7a6bc10 c0348818
> [ 84.040459] 1d80: 00000000 c0051864 60000013 c07c15d0 00000000 c7a6bc10
> c0fcf05c c7a6bc10
> [ 84.048674] 1da0: c0fcf05c c7a6bc44 00000002 00000000 c07c1564 c03494d0
> c07c1590 00536bb0
> [ 84.056888] 1dc0: c7a6bc10 c0fcf05c 00000000 c07c1564 00000000 c0349c14
> 00000000 c07e1684
> [ 84.065102] 1de0: 8061885f 00000013 8061885f 00000013 00000000 c005dec4
> 00000000 00000002
> [ 84.073316] 1e00: c0f91cc0 00000003 c0f91cc0 c07e1684 c069b6d8 c069b6fc
> c069b6fc c07e3d18
> [ 84.081529] 1e20: 00000000 c00599f8 00000003 00000000 00000000 c07a275c
> 60000013 00000004
> [ 84.089741] 1e40: 00000001 00000000 00000000 00000000 00000000 00000000
> 00000000 c07e1684
> [ 84.097956] 1e60: c07e1678 c069b6fc c6d20000 c07e3d18 00000000 c005e178
> c06e4fbc c6d21e9c
> [ 84.106168] 1e80: 00000002 c053539c 00000000 00000003 00000000 c07e1684
> c069b6d8 c069b6fc
> [ 84.114383] 1ea0: c069b6fc c07e3d18 00000000 c005a358 00000000 00000001
> 00000000 c07e1468
> [ 84.122596] 1ec0: 00000000 c0054efc 00000000 00000000 00000000 c0165f00
> 00000000 60000013
> [ 84.130812] 1ee0: c6d8c5c0 00000003 00000003 c0f91cc4 00000004 c6d20000
> c0696b14 c0058d1c
> [ 84.139027] 1f00: c6d15b80 00000004 c6d8c5c0 c6d8c5c0 c6d15b8c c6d20000
> c6d21f88 c02c7b38
> [ 84.147240] 1f20: c6d15b80 c0166da4 c6d15b80 01f8e408 00000004 c0165f74
> 00000000 00000000
> [ 84.155455] 1f40: 00000004 c6c39120 00000004 01f8e408 c6d21f88 c000f648
> 00000000 c010090c
> [ 84.163671] 1f60: c6e17da0 c6c39120 c6c39120 c6c39120 c6c39120 00000004
> 01f8e408 c000f648
> [ 84.171884] 1f80: 00000000 c0100b10 00000000 00000000 b6ef5b40 00000004
> 01f8e408 b6ef5b40
> [ 84.180097] 1fa0: 00000004 c000f460 00000004 01f8e408 00000001 01f8e408
> 00000004 00000000
> [ 84.188311] 1fc0: 00000004 01f8e408 b6ef5b40 00000004 00000004 01f8e408
> 00000004 00000000
> [ 84.196525] 1fe0: 00000000 bec9595c b6e2143c b6e7716c 60000010 00000001
> 00000000 00000000
> [ 84.204762] [<c0350a10>] (regmap_read) from [<c03d8ac4>]
> (mxs_phy_get_vbus_status+0x40/0x58)
> [ 84.213258] [<c03d8ac4>] (mxs_phy_get_vbus_status) from [<c03d8ca4>]
> (mxs_phy_suspend+0x54/0x120)
> [ 84.222185] [<c03d8ca4>] (mxs_phy_suspend) from [<c03d924c>]
> (ci_controller_suspend+0x40/0x60)
> [ 84.230847] [<c03d924c>] (ci_controller_suspend) from [<c03d93dc>]
> (ci_suspend+0x7c/0xbc)
> [ 84.239081] [<c03d93dc>] (ci_suspend) from [<c03401ac>]
> (platform_pm_suspend+0x2c/0x54)
> [ 84.247145] [<c03401ac>] (platform_pm_suspend) from [<c0348818>]
> (dpm_run_callback+0x48/0x12c)
> [ 84.255809] [<c0348818>] (dpm_run_callback) from [<c03494d0>]
> (__device_suspend+0x12c/0x370)
> [ 84.264294] [<c03494d0>] (__device_suspend) from [<c0349c14>]
> (dpm_suspend+0x134/0x2fc)
> [ 84.272350] [<c0349c14>] (dpm_suspend) from [<c00599f8>]
> (suspend_devices_and_enter+0x8c/0x6e4)
> [ 84.281094] [<c00599f8>] (suspend_devices_and_enter) from [<c005a358>]
> (pm_suspend+0x308/0x434)
> [ 84.289836] [<c005a358>] (pm_suspend) from [<c0058d1c>]
> (state_store+0x80/0xcc)
> [ 84.297192] [<c0058d1c>] (state_store) from [<c02c7b38>]
> (kobj_attr_store+0x18/0x1c)
> [ 84.304979] [<c02c7b38>] (kobj_attr_store) from [<c0166da4>]
> (sysfs_kf_write+0x48/0x4c)
> [ 84.313046] [<c0166da4>] (sysfs_kf_write) from [<c0165f74>]
> (kernfs_fop_write+0xe0/0x188)
> [ 84.321282] [<c0165f74>] (kernfs_fop_write) from [<c010090c>]
> (vfs_write+0xb8/0x1e8)
> [ 84.329074] [<c010090c>] (vfs_write) from [<c0100b10>]
> (SyS_write+0x44/0x88)
> [ 84.336178] [<c0100b10>] (SyS_write) from [<c000f460>]
> (ret_fast_syscall+0x0/0x48)
> [ 84.343791] Code: e92d4070 e1a04000 e1a05001 e1a00001 (e594117c)
> [ 84.350165] ---[ end trace 6acb90b2c2dd8be9 ]---
>
> The following patch fixed the issue for me, but i'm not sure that is the
> right fix
> for this issue since there are more platforms involved.
>
> -----------------------------------%<----------------------------------------------
> [PATCH] usb: phy: phy-mxs-usb: fix oops on suspend to RAM
>
> This patch avoids the oops in mxs_phy_get_vbus_status() by aborting since
> there is no syscon available.
>
> Signed-off-by: Stefan Wahren <stefan.wah...@i2se.com>
> Fixes: efdbd3a5d6e ("usb: phy: mxs: do not set PWD.RXPWD1PT1 for low
> speed
> connection")
> CC: <sta...@vger.kernel.org> # 4.0
> ---
> drivers/usb/phy/phy-mxs-usb.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
> index 8f7cb06..3fcc048 100644
> --- a/drivers/usb/phy/phy-mxs-usb.c
> +++ b/drivers/usb/phy/phy-mxs-usb.c
> @@ -217,6 +217,9 @@ static bool mxs_phy_get_vbus_status(struct mxs_phy
> *mxs_phy) {
> unsigned int vbus_value;
>
> + if (!mxs_phy->regmap_anatop)
> + return false;
> +
> if (mxs_phy->port_id == 0)
> regmap_read(mxs_phy->regmap_anatop,
> ANADIG_USB1_VBUS_DET_STAT,
> --
Stefan, Thanks for fixing it, it is a correct fix.
Acked-by: Peter Chen <peter.c...@freescale.com>
