Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754103Ab1ENKaS (ORCPT ); Sat, 14 May 2011 06:30:18 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:37349 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075Ab1ENKaM (ORCPT ); Sat, 14 May 2011 06:30:12 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=a8nPxf1DsZITv5rKx24Jeuj/jzASyxqa1V5ILWd5MzccpQh7kFwxiBoQW1UKPvbTOx aJBueUpcExMGwDBpiT9fyEOcfj7GJsYAl0yMxoyrUF2Qf72gj4gksYC7qJX8zUKPOgm8 wVlXzxqTM2B6Ye289QyghVfNb5AauaNUdqeVg= Date: Sat, 14 May 2011 12:28:04 +0200 From: Tejun Heo To: Linus Torvalds , Jeff Garzik Cc: Michael Leun , linux-ide@vger.kernel.org, Linux PM mailing list , LKML , "Rafael J. Wysocki" , Jeff Garzik , Jian Peng Subject: [PATCH v2.6.38-rc7] Revert "libata: ahci_start_engine compliant to AHCI spec" Message-ID: <20110514102804.GB23665@htj.dyndns.org> References: <201105120025.34531.rjw@sisk.pl> <201105132222.11582.rjw@sisk.pl> <201105132244.29605.rjw@sisk.pl> <20110514101807.GA23665@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110514101807.GA23665@htj.dyndns.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2117 Lines: 69 This reverts commit 270dac35c26433d06a89150c51e75ca0181ca7e4. The commits causes command timeouts on AC plug/unplug. It isn't yet clear why. As the commit was for a single rather obscure controller, revert the change for now. The problem was reported and bisected by Gu Rui in bug#34692. https://bugzilla.kernel.org/show_bug.cgi?id=34692 Also, reported by Rafael and Michael in the following thread. http://thread.gmane.org/gmane.linux.kernel/1138771 Signed-off-by: Tejun Heo Reported-by: Gu Rui Reported-by: Rafael J. Wysocki Reported-by: Michael Leun Cc: Jian Peng Cc: Jeff Garzik --- As we're already in -rc7, I'm sending the revert patch to both Jeff and Linus. Thank you. drivers/ata/libahci.c | 21 --------------------- 1 files changed, 0 insertions(+), 21 deletions(-) diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index ff9d832..d38c40f 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -561,27 +561,6 @@ void ahci_start_engine(struct ata_port *ap) { void __iomem *port_mmio = ahci_port_base(ap); u32 tmp; - u8 status; - - status = readl(port_mmio + PORT_TFDATA) & 0xFF; - - /* - * At end of section 10.1 of AHCI spec (rev 1.3), it states - * Software shall not set PxCMD.ST to 1 until it is determined - * that a functoinal device is present on the port as determined by - * PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h - * - * Even though most AHCI host controllers work without this check, - * specific controller will fail under this condition - */ - if (status & (ATA_BUSY | ATA_DRQ)) - return; - else { - ahci_scr_read(&ap->link, SCR_STATUS, &tmp); - - if ((tmp & 0xf) != 0x3) - return; - } /* start DMA */ tmp = readl(port_mmio + PORT_CMD); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/