From: Jeff Garzik <jeff@garzik.org>
To: Peer Chen <peerchen@gmail.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
akpm <akpm@linux-foundation.org>,
linux-ide <linux-ide@vger.kernel.org>
Subject: Re: [PATCH] ahci: enable GHC.AE bit before set GHC.HR
Date: Wed, 26 Sep 2007 00:03:19 -0400 [thread overview]
Message-ID: <46F9DA07.4080201@garzik.org> (raw)
In-Reply-To: <200709211327569648280@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 755 bytes --]
Peer Chen wrote:
> According to the description of section 5.2.2.1 and 10.1.2 of AHCI specification rev1_1/rev1_2, GHC.HR shall only be set to ¡®1¡¯
> by software when GHC.AE is set to ¡®1¡¯.
>
> Signed-off-by: Peer Chen <peerchen@gmail.com>
> ---
> --- linux-2.6.23-rc7/drivers/ata/ahci.c.orig 2007-09-20 11:01:55.000000000 -0400
> +++ linux-2.6.23-rc7/drivers/ata/ahci.c 2007-09-20 11:07:31.000000000 -0400
> @@ -834,6 +834,10 @@ static int ahci_reset_controller(struct
> void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
> u32 tmp;
>
> + /* turn on AHCI mode before controller reset*/
> + writel(HOST_AHCI_EN, mmio + HOST_CTL);
> + (void) readl(mmio + HOST_CTL); /* flush */
applied the attached patch, inspired by yours.
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[-- Type: text/plain, Size: 1180 bytes --]
commit 5fca365d6109b51cfeb3515ca660cd2dc6e8822c
Author: Jeff Garzik <jeff@garzik.org>
Date: Wed Sep 26 00:02:41 2007 -0400
[libata] AHCI: enable AHCI mode, before using AHCI reset
AHCI spec says host-reset bit may only be set when the ahci-enable bit
is also set.
Noticed by Peer Chen <peerchen@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
drivers/ata/ahci.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
5fca365d6109b51cfeb3515ca660cd2dc6e8822c
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 9f3c591..b615390 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -827,8 +827,14 @@ static int ahci_reset_controller(struct ata_host *host)
void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
u32 tmp;
- /* global controller reset */
+ /* we must be in AHCI mode, before using anything
+ * AHCI-specific, such as HOST_RESET.
+ */
tmp = readl(mmio + HOST_CTL);
+ if (!(tmp & HOST_AHCI_EN))
+ writel(tmp | HOST_AHCI_EN, mmio + HOST_CTL);
+
+ /* global controller reset */
if ((tmp & HOST_RESET) == 0) {
writel(tmp | HOST_RESET, mmio + HOST_CTL);
readl(mmio + HOST_CTL); /* flush */
next prev parent reply other threads:[~2007-09-26 4:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-21 5:28 [PATCH] ahci: enable GHC.AE bit before set GHC.HR Peer Chen
2007-09-21 10:29 ` Andrew Morton
2007-09-21 10:31 ` Jens Axboe
2007-09-21 11:27 ` Alan Cox
2007-09-21 11:34 ` Jens Axboe
2007-09-26 4:03 ` Jeff Garzik [this message]
2007-09-26 11:23 ` Alan Cox
2007-09-26 11:41 ` Jeff Garzik
2007-09-26 14:30 ` Alan Cox
2007-09-26 14:33 ` Jeff Garzik
2007-09-26 16:10 ` Alan Cox
2007-09-26 16:20 ` Jeff Garzik
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