From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: System hangs when using USB 3.0 HD with on Ubuntu Date: Fri, 02 Apr 2010 19:50:15 +0400 Message-ID: <4BB61237.5030000@ru.mvista.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alan Stern Cc: James Bottomley , Jonas Schwertfeger , Kay Sievers , Douglas Gilbert , David Zeuthen , linux-hotplug-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sarah Sharp , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, USB Storage List , Matthew Dharm , linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Lennart Poettering List-Id: linux-scsi@vger.kernel.org Hello. Alan Stern wrote: >>> Best guess (and it's a guess only) would be that the USB bridge SAT >>> layer doesn't implement ATA_16 and so fails in interesting ways when it >>> comes in. Does the ATA_12 version of IDENTIFY DEVICE succeed? >>> >> It does. And in between the two is an ATA_16 SET FEATURES command >> which also (apparently) succeeds. That is, there is no error >> indication from the device -- but goodness knows if it actually carries >> out the command. >> > > Incidentally, there's a discussion of this problem with input from an > engineer at the company that makes the bridge chip here: > > https://bugs.launchpad.net/ubuntu/+source/linux-fsl-imx51/+bug/431963 > > See comment #25 and later. He claims that the ATA pass-through command > contains a SECTOR COUNT field of 0 even though it asks for 512 bytes of > IDENTIFY data. This invalid parameter combination causes the bridge > chip to get confused, and instead of failing gracefully, it messes up > the USB protocol. > IDENTIFY DEVICE command always returns 512 bytes of data, regardless of any value in the sector count register. > Does anybody know where to find out why hdparm is sending an IDENTIFY > command with invalid parameters? > IDENTIFY DEVICE command has *no* parameters. > Alan Stern > WBR, Sergei -- 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