From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: [usb-storage] Re: [PATCH 04/14] uas: lock the abort handler Date: Wed, 03 Feb 2016 15:28:56 +0100 Message-ID: <1454509736.1930.9.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: Hans de Goede , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kraxel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mdharm-usb-JGfshJpz5UybPZpvUQj5UqxOck334EZe@public.gmane.org, usb-storage-ijkIwGHArpdIPJnuZ7Njw4oP9KaGy4wf@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-scsi@vger.kernel.org On Tue, 2016-01-26 at 10:28 -0500, Alan Stern wrote: > On Tue, 26 Jan 2016, Oliver Neukum wrote: > > That is problematic. The ABORT_TMF does need IO for which we need > > to wait. And if we just submit and pretend the abort worked, the tag > > will be reused. > > Perhaps we could drop the spinlock. I think it is time to talk to > > the SCSI people. > > The abort handler doesn't have to wait for the command to terminate. > It merely has to initiate an abort and return. The SCSI layer gets > notified via the usual mechanism when the command eventually finishes, > whether it was successful or not. This is stange. I don't see how we can guarantee a command completion if eh_abort_handler() has sent the TMF. It was my understanding that returning from eh_abort_handler() means that a tag is considered free again and will be reused. Could you clarify? 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