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[PATCH] Au1xx0: replace casual readl() with au_readl() in the drivers

To: Andrew Morton <akpm@osdl.org>
Subject: [PATCH] Au1xx0: replace casual readl() with au_readl() in the drivers
From: Sergei Shtylylov <sshtylyov@ru.mvista.com>
Date: Sat, 31 Dec 2005 02:07:59 +0300
Cc: Linux MIPS Development <linux-mips@linux-mips.org>, Jordan Crouse <jordan.crouse@amd.com>, ralf@linux-mips.org
In-reply-to: <436FB1DE.6010405@ru.mvista.com>
Organization: MostaVista Software Inc.
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <43452054.2090305@ru.mvista.com> <436FB1DE.6010405@ru.mvista.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.2) Gecko/20040803
Hello, I wrote:

    We have found some issues with Au1550 AC'97 OSS driver in 2.6
(sound/oss/au1550_ac97.c), though it also should concern 2.4 driver
(drivers/sound/au1550_psc.c).
First, we don't think that using readl() calls instead of au_readl() is
correct -- readl() is subject to byte-swapping etc., so may not work in
BE mode anymore and au_readl() is intended for embedded Au1550 devices
for which the byte swapping issue is resolved automagically,  and BTW the same
PSC_AC97STAT register is read "both ways" in the driver.

[skipped]

    Additionally, I've found one unjustified call to readl() in the Au1xx0 USB
code, so adding the fix for it to the patch. Andrew, I'm sending the patch to
you as was advised by Ralf and Jordan...

WBR, Sergei

diff --git a/drivers/usb/host/ohci-au1xxx.c b/drivers/usb/host/ohci-au1xxx.c
index 486202d..0fc728e 100644
--- a/drivers/usb/host/ohci-au1xxx.c
+++ b/drivers/usb/host/ohci-au1xxx.c
@@ -66,7 +66,7 @@ static void au1xxx_stop_hc(struct platfo
               ": stopping Au1xxx OHCI USB Controller\n");
 
        /* Disable clock */
-       au_writel(readl((void *)USB_HOST_CONFIG) & ~USBH_ENABLE_CE, 
USB_HOST_CONFIG);
+       au_writel(au_readl(USB_HOST_CONFIG) & ~USBH_ENABLE_CE, USB_HOST_CONFIG);
 }
 
 
diff --git a/sound/oss/au1550_ac97.c b/sound/oss/au1550_ac97.c
index f70effd..64e2e46 100644
--- a/sound/oss/au1550_ac97.c
+++ b/sound/oss/au1550_ac97.c
@@ -463,7 +463,7 @@ stop_dac(struct au1550_state *s)
        /* Wait for Transmit Busy to show disabled.
        */
        do {
-               stat = readl((void *)PSC_AC97STAT);
+               stat = au_readl(PSC_AC97STAT);
                au_sync();
        } while ((stat & PSC_AC97STAT_TB) != 0);
 
@@ -492,7 +492,7 @@ stop_adc(struct au1550_state *s)
        /* Wait for Receive Busy to show disabled.
        */
        do {
-               stat = readl((void *)PSC_AC97STAT);
+               stat = au_readl(PSC_AC97STAT);
                au_sync();
        } while ((stat & PSC_AC97STAT_RB) != 0);
 
@@ -542,7 +542,7 @@ set_xmit_slots(int num_channels)
        /* Wait for Device ready.
        */
        do {
-               stat = readl((void *)PSC_AC97STAT);
+               stat = au_readl(PSC_AC97STAT);
                au_sync();
        } while ((stat & PSC_AC97STAT_DR) == 0);
 }
@@ -574,7 +574,7 @@ set_recv_slots(int num_channels)
        /* Wait for Device ready.
        */
        do {
-               stat = readl((void *)PSC_AC97STAT);
+               stat = au_readl(PSC_AC97STAT);
                au_sync();
        } while ((stat & PSC_AC97STAT_DR) == 0);
 }
@@ -1996,7 +1996,7 @@ au1550_probe(void)
        /* Wait for PSC ready.
        */
        do {
-               val = readl((void *)PSC_AC97STAT);
+               val = au_readl(PSC_AC97STAT);
                au_sync();
        } while ((val & PSC_AC97STAT_SR) == 0);
 
@@ -2019,7 +2019,7 @@ au1550_probe(void)
        /* Wait for Device ready.
        */
        do {
-               val = readl((void *)PSC_AC97STAT);
+               val = au_readl(PSC_AC97STAT);
                au_sync();
        } while ((val & PSC_AC97STAT_DR) == 0);
 
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