Re: [PATCH] usb: cdns3: fix race condition before setting doorbell

[Greg KH <greg@kroah.com>]

On Thu, Sep 30, 2021 at 11:42:17AM +0200, Pawel Laszczak wrote:
> From: Pawel Laszczak <pawell@cadence.com>
> 
> commit b69ec50b3e55c4b2a85c8bc46763eaf33060584 upstream
> 
> For DEV_VER_V3 version there exist race condition between clearing
> ep_sts.EP_STS_TRBERR and setting ep_cmd.EP_CMD_DRDY bit.
> Setting EP_CMD_DRDY will be ignored by controller when
> EP_STS_TRBERR is set. So, between these two instructions we have
> a small time gap in which the EP_STS_TRBERR can be set. In such case
> the transfer will not start after setting doorbell.
> 
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> cc: <stable@vger.kernel.org> # 5.4.x
> Tested-by: Aswath Govindraju <a-govindraju@ti.com>
> Reviewed-by: Aswath Govindraju <a-govindraju@ti.com>
> Signed-off-by: Pawel Laszczak <pawell@cadence.com>
> ---
>  drivers/usb/cdns3/gadget.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)

What kernel(s) are you wanting this applied to?

thanks,

greg k-h