From 66583c9fa63d05d5580e409f9a58d3cad6d76d17 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 21 Feb 2012 10:38:42 -0800 Subject: ahci: add AHCI_HFLAG_DELAY_ENGINE host flag The following commit was intended to fix problems with specific AHCI controller(s) that would become bricks if the AHCI specification was not followed strictly (that is, if ahci_start_engine() was called while the controller was in the wrong state): 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 delays the ahci_start_engine() call only for specific controllers. This commit simply introduces the flag, without enabling it in any driver. Note that even when AHCI_HFLAG_DELAY_ENGINE is not enabled, 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 Signed-off-by: Jeff Garzik Cc: stable@kernel.org --- drivers/ata/ahci.h | 3 +++ drivers/ata/libahci.c | 5 +++++ 2 files changed, 8 insertions(+) (limited to 'drivers/ata') diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index b1750007c8dc..feb127ef4e4e 100644 --- a/drivers/ata/ahci.h +++ b/drivers/ata/ahci.h @@ -210,6 +210,9 @@ 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_DELAY_ENGINE = (1 << 15), /* do not start engine on + port start (wait until + error-handling stage) */ /* ap->flags bits */ diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index a72bfd0ecfee..f9eaa82311a9 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_DELAY_ENGINE)) + ahci_start_engine(ap); + /* turn on LEDs */ if (ap->flags & ATA_FLAG_EM) { ata_for_each_link(link, ap, EDGE) { -- cgit v1.2.1