From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49777) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZMJ6r-0007Nq-6X for qemu-devel@nongnu.org; Mon, 03 Aug 2015 13:01:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZMJ6l-0008Sz-4v for qemu-devel@nongnu.org; Mon, 03 Aug 2015 13:01:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50831) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZMJ6k-0008St-Vx for qemu-devel@nongnu.org; Mon, 03 Aug 2015 13:01:03 -0400 Message-ID: <55BF9E4C.5020706@redhat.com> Date: Mon, 03 Aug 2015 13:01:00 -0400 From: John Snow MIME-Version: 1.0 References: <1438448070-32552-1-git-send-email-mark.cave-ayland@ilande.co.uk> <20150801183337.GA10456@aurel32.net> <55BD15F7.5090400@ilande.co.uk> In-Reply-To: <55BD15F7.5090400@ilande.co.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark Cave-Ayland , Aurelien Jarno Cc: agraf@suse.de, qemu-devel@nongnu.org On 08/01/2015 02:54 PM, Mark Cave-Ayland wrote: > On 01/08/15 19:33, Aurelien Jarno wrote: > >> On 2015-08-01 17:54, Mark Cave-Ayland wrote: >>> The existing code incorrectly changes the dma_active flag when a non-block >>> transfer has completed leading to a hang on newer versions of Linux because the >>> IDE and DMA engines deadlock waiting for each other. >>> >>> Instead copy the buffer directly to RAM, set the remaining transfer size to 0 and >>> then invoke the ATAPI callback manually once again to correctly finish the >>> transfer in an identical manner to a block transfer. >>> >>> Signed-off-by: Mark Cave-Ayland >>> --- >> >> Thanks for the patch, it improves things here. I don't get messages >> anymore, and I get less messages when mounting the CD-ROM, though I >> still get one: >> >> [ 307.258463] pata-macio 0.00021000:ata-4: timeout flushing DMA >> [ 307.262856] ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0 >> [ 307.262919] ata2.00: BMDMA stat 0x6 >> [ 307.263048] sr 1:0:0:0: CDB: Get configuration: 46 00 00 28 00 00 00 00 10 00 >> [ 307.263289] ata2.00: cmd a0/01:00:00:10:00/00:00:00:00:00/a0 tag 0 dma 16400 in >> [ 307.263297] res 41/50:03:00:10:00/00:00:00:00:00/a0 Emask 0x20 (host bus error) >> [ 307.263407] ata2.00: status: { DRDY ERR } >> [ 307.271251] ata2.00: configured for MWDMA2 >> [ 307.271824] ata2: EH complete >> >> The CD-ROM is fully functional though. > > Hmmmm yes I can recreate that here - must be another transition between > the non-block and the block transfer code (I was working on eliminating > the boot messages) caused by reading the disc metadata upon mount. > Unfortunately I don't have much time to work on this right now so maybe > it's a 2.4.1/2.5 thing unless John can take a look? > > > ATB, > > Mark. > Definitely a 2.4.1/2.5 thing anyway at this time. If you prepare a v3 to nail down the last state transition error message you're seeing, just CC stable as well, and I'll handle it for 2.5. --js