From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lenehan Subject: Re: dc395x: can't write to tape Date: Sun, 9 Jan 2005 23:51:17 +1100 Message-ID: <20050109125116.GA6293@twibble.org> References: <200501060518.25782.andrex@alumni.utexas.net> <20050109053342.GA5799@twibble.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from nynaeve.twibble.org ([202.173.155.194]:33955 "EHLO nynaeve.twibble.org") by vger.kernel.org with ESMTP id S261377AbVAIMvT (ORCPT ); Sun, 9 Jan 2005 07:51:19 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Guennadi Liakhovetski Cc: Andrew Schulman , linux-scsi@vger.kernel.org On Sun, Jan 09, 2005 at 12:42:26PM +0100, Guennadi Liakhovetski wrote: [...] > The driver is full of "hardware bug workarounds". Jamie, are those PIO > operations really needed? Do you ever see, that DMA doesn't transfer the > last 1-3 bytes of the segment? What I suspect those workarounds were added for was to handle a driver bug with dealing with WIDE transfers. The dc315 doesn't support WIDE transfers and that's the card I have. I wouldn't mind removing all the PIO code and disabling support for WIDE devices. It'll simplify various bits of code a lot and mean no longer having to be concered about breaking things for the dc395 when making changes. [...] > I could try to improve the highmem situation / sg-handling. Or do you plan > to do it, Jamie? It's on my list of things to do, but I doubt I'll have any time to do anything about in the next few months. So if you have the time and desire please go ahead! I'll can test any changes you make (with a CD-R/W, tape-drive and HDD), although it may take me a week or two to get around to it. -- Jamie Lenehan