[PATCH 1/3] ahci: add AHCI_HFLAG_STRICT_SPEC host flag
From: Brian Norris <computersforpeace@gmail.com>
Date: 2012-02-20 20:10:10
Also in:
lkml
Subsystem:
libata subsystem (serial and parallel ata drivers), the rest · Maintainers:
Damien Le Moal, Niklas Cassel, Linus Torvalds
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 <computersforpeace@gmail.com>
---
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) {