Re: [PATCH] usb: cdns3: Fix: ARM core hang after connect/disconnect operation.

From: Greg KH
Date: Wed Jan 08 2020 - 09:22:54 EST


On Wed, Jan 08, 2020 at 12:37:18PM +0100, Pawel Laszczak wrote:
> The ARM core hang when access USB register after tens of thousands
> connect/disconnect operation.
>
> The issue was observed on platform with android system and is not easy
> to reproduce. During test controller works at HS device mode with host
> connected.
>
> The test is based on continuous disabling/enabling USB device function
> what cause continuous setting DEVDS/DEVEN bit in USB_CONF register.
>
> For testing was used composite device consisting from ADP and RNDIS
> function.
>
> Presumably the problem was caused by DMA transfer made after setting
> DEVDS bit. To resolve this issue fix stops all DMA transfer before
> setting DEVDS bit.
>
> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
> Signed-off-by: Peter Chan <peter.chan@xxxxxxx>
> Reported-by: Peter Chan <peter.chan@xxxxxxx>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> ---
> drivers/usb/cdns3/gadget.c | 84 ++++++++++++++++++++++++++------------
> drivers/usb/cdns3/gadget.h | 1 +
> 2 files changed, 58 insertions(+), 27 deletions(-)

Any reason to forget linux-usb@xxxxxxxxxxxxxxx for usb patches?

thanks,

greg k-h