Re: [PATCH v2 1/1] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers

From: Bin Liu
Date: Mon Mar 05 2018 - 12:38:13 EST


On Wed, Feb 28, 2018 at 01:59:43PM -0800, Tony Lindgren wrote:
> * Merlijn Wajer <merlijn@xxxxxxxxxx> [180227 22:29]:
> > Without pm_runtime_{get,put}_sync calls in place, reading
> > vbus status via /sys causes the following error:
> >
> > Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
> > pgd = b333e822
> > [fa0ab060] *pgd=48011452(bad)
> >
> > [<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
> > [<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
> > [<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
> > [<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
> > [<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
> > [<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
> > [<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
> > [<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)
> >
> > Solution was suggested by Tony Lindgren <tony@xxxxxxxxxxx>.
> >
> > Signed-off-by: Merlijn Wajer <merlijn@xxxxxxxxxx>
>
> Thanks for fixing this. Assuming it passes Bin's tests:
>
> Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>

Applied and sent out. Thanks.

-Bin.