From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Subject: "ahci: drop intx manipulation on msi enable" breaks ULI M1575 Date: Tue, 07 Apr 2009 09:54:12 -0500 Message-ID: <49DB6914.1030107@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from az33egw02.freescale.net ([192.88.158.103]:61163 "EHLO az33egw02.freescale.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757547AbZDGOzQ (ORCPT ); Tue, 7 Apr 2009 10:55:16 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: tj@kernel.org, linux-ide@vger.kernel.org Tejun, Your patch > ahci: drop intx manipulation on msi enable > > There's no need to turn off intx explicitly on msi enable. This is > automatically handled by pci. Drop it. > > This might be needed on machines if the BIOS turns intx off during > boot. However, there's no evidence of such behavior for ahci and > the only such case seems to be ICH5 PATA according to ata_piix. > Also, given the way ahci operates, it's highly unlikely BIOS ever > disables IRQ for the controller. However, as this change has slight > possibility of introducing failure, please schedule it for #upstream. breaks SATA support on a Freescale MPC8610 HPCD (PowerPC) reference board. When I apply the patch, I get this result during boot: ata1: SATA max UDMA/133 irq_stat 0x00400040, connection status changed irq 19 ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata1.00: qc timeout (cmd 0xec) ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4) ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata1.00: qc timeout (cmd 0xec) ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4) ata1: limiting SATA link speed to 1.5 Gbps ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310) ata1.00: qc timeout (cmd 0xec) ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4) ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310) This board uses a ULI M1575 for SATA support. Unfortunately, I don't know enough about SATA or PCI interrupts to understand why you made the change or why it breaks on my board. -- Timur Tabi Linux kernel developer at Freescale