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SubjectRe: [RFC] usb issue on imx27: 3 clocks are needed
Hi Philippe,

On Sat, Aug 16, 2014 at 12:38 PM, Philippe Reynes <> wrote:
> Hi all,
> i.MX27's usb needs three clocks (usb_ipg_gate, usb_ahb_gate and usb_div)
> but the current chipidea driver implementation, and devicetree, provides
> only ipg and ahb. Consequently, if the bootloader don't enable the last
> one, the kernel will crash.

Which kernel version and what is the crash log you are getting?

I used to get a USB crash on mx27, which was fixed with the following commit:

commit b67b19447eb4f60d4f004f48298154630d4bed39
Author: Fabio Estevam <>
Date: Wed Apr 16 14:53:18 2014 -0300

ARM: dts: imx27: Use the correct usb clock gate

USB Host1, Host2 and OTG are gated via 'usb_ipg_gate' clock, so
fix it in order
to avoid the following kernel oops:

usbcore: registered new interface driver usb-storage
10024000.usb supply vbus not found, using dummy regulator
Unhandled fault: external abort on non-linefetch (0x808) at 0xf4424184
Internal error: : 808 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 3.15.0-rc1-26325-g971f9fd-dirty #64
task: c7829aa0 ti: c7836000 task.ti: c7836000
PC is at ci_hdrc_probe+0x3a4/0x634
LR is at ci_hdrc_probe+0x100/0x634
pc : [<c036cc78>] lr : [<c036c9d4>] psr: 60000013
sp : c7837d48 ip : 00000001 fp : 00000000
r10: 00000000 r9 : 00000000 r8 : c791b6c0
r7 : c7945000 r6 : f4424000 r5 : c7945010 r4 : c794e010
r3 : f4424184 r2 : 00000000 r1 : 8c000004 r0 : 0c000004
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 0005317f Table: a0004000 DAC: 00000017
Process swapper (pid: 1, stack limit = 0xc78361c0)
Stack: (0xc7837d48 to 0xc7838000)

Signed-off-by: Fabio Estevam <>
Signed-off-by: Shawn Guo <>

Do you have this one applied?

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