From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: JMS56x not working reliably with uas driver Date: Tue, 27 Dec 2016 16:53:43 +0100 Message-ID: <1482854023.1731.4.camel@suse.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alan Stern Cc: George Cherian , hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-scsi@vger.kernel.org On Tue, 2016-12-27 at 10:20 -0500, Alan Stern wrote: > On Tue, 27 Dec 2016, Oliver Neukum wrote: > > > On Thu, 2016-12-22 at 17:44 -0500, Alan Stern wrote: > > > I don't see how this patch fixes anything. Unless I'm mistaken, it > > > just avoids the problem by preventing the system from issuing the > > > command that provokes the error, rather than really fixing the > > > underlying error. > > > > Please clarify. If a reset leads to a disconnect, isn't that > > exactly what we want? > > I didn't express myself clearly enough. Yes, if a reset leads to a > disconnect then avoiding the reset will avoid problems. Good. Then we need to clarify whether the device was physically disconnected when the logs were taken. > But the _real_ error here is that xhci-hcd says "ERROR Transfer event > for disabled endpoint or incorrect stream ring" when the disconnect > occurs during reset. That shouldn't happen, no matter what quirks the > device has. It indicates a bug either in uas or in xhci-hcd. True. I am afraid that there necessarily is a window for resetting a disconnected device. But the check you proposed is better. however, I'd like to encapsulate that together with a test for logical disconnect. Uas is unlikely to be the only driver that has this issue. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html