From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] libata error handling fixes (ATAPI) Date: Tue, 15 Nov 2005 09:11:14 -0500 Message-ID: <4379EC82.1030509@pobox.com> References: <20051114195717.GA24373@havoc.gtf.org> <20051115074148.GA17459@htj.dyndns.org> <4379AA5B.1060900@pobox.com> <4379E5F7.6000107@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dvmed.net ([216.237.124.58]:39080 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932389AbVKOOLT (ORCPT ); Tue, 15 Nov 2005 09:11:19 -0500 In-Reply-To: <4379E5F7.6000107@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, Carlos Pardo Tejun Heo wrote: > * prb->fis doesn't contain proper signature after phy reset. I just This makes sense. Each PRB slot in the card's RAM only contains something useful after you have submitted a PRB, and had some results returned. > * As all commands hang after failed TUR, which BTW fails rightfully with > 06h (UNIT ATTENTION due to prior reset) and then 02h's (NOT READY), I > avoided TUR failures by issuing REQUEST SENSE first, which returns NO > SENSE but does clear UA condition, and then waiting for more than 10secs > to give the drive time to become ready. 10 seconds is certainly a long time. grep for msleep(150) in libata code, though. > * With above two changes, no command fails and I can mount the cdrom. > > ------------------ > > And here are things that I've found out so far.... > > * ATAPI commands without data (TEST_UNIT_READY, ALLOW_MEDIUM_REMOVAL...) > work happily with any prb->ctrl flag (no flag, PRB_CTRL_PACKET_READ or > PRB_CTRL_PACKET_WRITE). I suppose no-flag is the right answer, then... > * Currently, sil24_reset_controller() is called on every error interrupt > to make sure the controller is ready for further operation. > Unfortunately, the current reset_controller() seems to reset PHY too. > The drive becomes NOT READY after reset_controller(). So, when TUR > fails, it falls into TUR, fail with NOT READY, reset which makes the > drive NOT READY again cycle. Standard init sequence includes checking SStatus, then if a device is present, waiting until Port Ready (bit 31) of PORT_CTRL_STAT is set. It doesn't look like sata_sil24 does that. > * Wihtout sil24_reset_controller(), no further command can be issued. > The controller doesn't seem to be operating normally after DEV_ERR. The port stops, when any error occurs. For device errors, set PORT_CS_INIT bit in PORT_CTRL_STAT, then wait for Port Ready (bit 31, see above). > So, what we need to know to make sil24 work happily with ATAPI devices. > > * How to get device signature on initialization. AFAICS, you _must_ send a soft reset PRB. This will be needed anyway, for port multiplier support. > * How to make the controller operational again after a DEV_ERR without > affecting the attached device. Assert PORT_CS_INIT, then wait for Port Ready. __ONLY__ do this for errors PORT_CERR_DEV and PORT_CERR_SDB. Jeff