From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Norris Subject: [PATCH 1/3] ahci: add AHCI_HFLAG_STRICT_SPEC host flag Date: Mon, 20 Feb 2012 12:09:21 -0800 Message-ID: <1329768563-13715-2-git-send-email-computersforpeace@gmail.com> References: <1329768563-13715-1-git-send-email-computersforpeace@gmail.com> Return-path: Received: from mail-pz0-f46.google.com ([209.85.210.46]:33447 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752512Ab2BTUKG (ORCPT ); Mon, 20 Feb 2012 15:10:06 -0500 In-Reply-To: <1329768563-13715-1-git-send-email-computersforpeace@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: linux-ide@vger.kernel.org, Linux Kernel , Tejun Heo , Kevin Cernekee , Brian Norris , Lin Ming , Norbert Preining , "Srivatsa S . Bhat" , Valdis Kletnieks , "Rafael J . Wysocki" The following commit was intended to fix problems with some specific AHCI platforms that would become bricks if the AHCI specification was not followed strictly: commit 7faa33da9b7add01db9f1ad92c6a5d9145e940a7 ahci: start engine only during soft/hard resets However, some devices currently have issues with that fix, so we must implement a flag that enables the fix only for specific controllers. This commit simply introduces the flag, without enabling it in any driver. Note that even when AHCI_HFLAG_STRICT_SPEC is not set, this patch does not constitue a full revert to commit 7faa33da; there is still a change in behavior to the ahci_port_suspend() failure path. Signed-off-by: Brian Norris --- drivers/ata/ahci.h | 1 + drivers/ata/libahci.c | 5 +++++ 2 files changed, 6 insertions(+), 0 deletions(-) diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index b175000..9c8aed0 100644 --- a/drivers/ata/ahci.h +++ b/drivers/ata/ahci.h @@ -210,6 +210,7 @@ enum { AHCI_HFLAG_NO_SNTF = (1 << 12), /* no sntf */ AHCI_HFLAG_NO_FPDMA_AA = (1 << 13), /* no FPDMA AA */ AHCI_HFLAG_YES_FBS = (1 << 14), /* force FBS cap on */ + AHCI_HFLAG_STRICT_SPEC = (1 << 15), /* strict AHCI spec */ /* ap->flags bits */ diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index a72bfd0..f59abd0 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -737,6 +737,7 @@ static void ahci_power_down(struct ata_port *ap) static void ahci_start_port(struct ata_port *ap) { + struct ahci_host_priv *hpriv = ap->host->private_data; struct ahci_port_priv *pp = ap->private_data; struct ata_link *link; struct ahci_em_priv *emp; @@ -746,6 +747,10 @@ static void ahci_start_port(struct ata_port *ap) /* enable FIS reception */ ahci_start_fis_rx(ap); + /* enable DMA */ + if (!(hpriv->flags & AHCI_HFLAG_STRICT_SPEC)) + ahci_start_engine(ap); + /* turn on LEDs */ if (ap->flags & ATA_FLAG_EM) { ata_for_each_link(link, ap, EDGE) {