Re: [PATCH] drivers: usb: host: Fix GFP_KERNEL in spinlock context

From: Greg KH
Date: Fri Dec 22 2017 - 02:13:23 EST


On Fri, Dec 22, 2017 at 11:19:24AM +0530, shrikant.maurya@xxxxxxxxxxxx wrote:
> From: Shrikant Maurya <shrikant.maurya@xxxxxxxxxxxx>
>
> As reported by Jia-Ju Bai (https://lkml.org/lkml/2017/12/11/872):
> API's are using GFP_KERNEL to allocate memory, which may sleep.
> To ensure atomicity such allocations must be avoided in critical
> sections under spinlock.
> Fixed by moving part of the code which is using GFP_KERNEL for
> memory allocation out of spinlock.
>
> Reported-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> Signed-off-by: Shrikant Maurya <shrikant.maurya@xxxxxxxxxxxx>
> Signed-off-by: Suniel Mahesh <sunil.m@xxxxxxxxxxxx>
> Signed-off-by: Raghu Bharadwaj <raghu@xxxxxxxxxxxx>
> Signed-off-by: Karthik Tummala <karthik@xxxxxxxxxxxx>
> ---
> Note:
> - trace of device_init_wakeup() leads to creation of a struct
> wakeup_source object and addition of the object to the list
> of wakeup sources. While allocating wakeup_source object, API
> is using GFP_KERNEL. This particular section is removed out of
> spinlock.
> - Changeset was compile tested and built(ARCH=arm) on linux-next
> (latest).
> - No build issues reported.
> - Changeset was not tested on hardware.

No one was able to test on the hardware itself? Ideally I'd like to see
that happen to verify nothing breaks here. No one has this chip on any
devices?

thanks,

greg k-h