From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: libata_uli puts second channel to PIO4 on 2.6.18 Date: Wed, 07 Feb 2007 14:19:48 +0900 Message-ID: <45C96174.2030407@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0506.google.com ([64.233.162.230]:64965 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030287AbXBGRzV (ORCPT ); Wed, 7 Feb 2007 12:55:21 -0500 Received: by nz-out-0506.google.com with SMTP id s1so246643nze for ; Wed, 07 Feb 2007 09:55:21 -0800 (PST) In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Grzegorz Kulewski Cc: Jeff Garzik , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Grzegorz Kulewski wrote: > It worked very well for half a year but with one disk (IIRC it was even > plugged into second channel but I wont bet on it). Now I have second > disk (very similar) and it is always put into PIO4 mode: > > [ 17.404451] libata version 2.00 loaded. > [ 17.404916] sata_uli 0000:00:04.0: version 1.0 > [ 17.405009] ACPI: PCI Interrupt 0000:00:04.0[A] -> GSI 18 (level, > low) -> IRQ 185 > [ 17.405223] ata1: SATA max UDMA/133 cmd 0xD400 ctl 0xD002 bmdma > 0xB000 irq 185 > [ 17.405385] ata2: SATA max UDMA/133 cmd 0xB800 ctl 0xB402 bmdma > 0xB008 irq 185 > [ 17.405519] scsi2 : sata_uli > [ 17.858803] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310) > [ 17.880541] ata1.00: ATA-7, max UDMA/133, 488397168 sectors: LBA48 > NCQ (depth 0/32) > [ 17.880660] ata1.00: ata1: dev 0 multi count 16 > [ 17.888858] ata1.00: configured for UDMA/133 > [ 17.888941] scsi3 : sata_uli > [ 18.342469] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 310) > [ 18.343573] ata2.00: ATA-7, max UDMA/133, 488397168 sectors: LBA48 > NCQ (depth 0/32) > [ 18.343691] ata2.00: ata2: dev 0 multi count 16 > [ 18.344972] ata2.00: configured for PIO4 Some uli controllers have simplex bit stuck high indicating that they can't perform DMA transfers simultaneously on both channels. In this case, libata configures the second channel as PIO only. This has been worked around by the following commit. commit b2a8bbe67d73631c71492fd60b757fc50a87f182 Author: Tejun Heo Date: Thu Jan 25 19:40:05 2007 +0900 libata: implement ATA_FLAG_IGN_SIMPLEX and use it in sata_uli Some uli controllers have stuck SIMPLEX bit which can't be cleared with ata_pci_clear_simplex(), but the controller is capable of doing DMAs on both channels simultaneously. Implement ATA_FLAG_IGN_SIMPLEX which makes libata ignore the simplex bit and use it in sata_uli. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik For quick fix, just comment out lines which set ATA_HOST_SIMPLEX in drivers/scsi/libata-bmdma.c. e.g. /*if (inb(bmdma + 2) & 0x80) probe_ent->host_set_flags |= ATA_HOST_SIMPLEX;*/ -- tejun