[PATCH 1/2] hpt366: add debounce delay to cable_detect() method

[PATCH 1/2] hpt366: add debounce delay to cable_detect() method

[Sergei Shtylyov]

Alan Cox reported that cable detection sometimes works unreliably
for HPT3xxN and that the issue is fixed by adding debounce delay
as used by the vendor drivers.

While at it, get rid of unneeded parens/space in the vicinity...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: stable@kernel.org

---
The patcn is atop of ide-2.6.git tree...

 drivers/ide/hpt366.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

Index: ide-2.6/drivers/ide/hpt366.c
===================================================================
--- ide-2.6.orig/drivers/ide/hpt366.c
+++ ide-2.6/drivers/ide/hpt366.c
@@ -1173,8 +1173,9 @@ static u8 hpt3xx_cable_detect(ide_hwif_t
 		u16 mcr;
 
 		pci_read_config_word(dev, mcr_addr, &mcr);
-		pci_write_config_word(dev, mcr_addr, (mcr | 0x8000));
-		/* now read cable id register */
+		pci_write_config_word(dev, mcr_addr, mcr | 0x8000);
+		/* Debounce, then read cable ID register */
+		udelay(10);
 		pci_read_config_byte(dev, 0x5a, &scr1);
 		pci_write_config_word(dev, mcr_addr, mcr);
 	} else if (chip_type >= HPT370) {
@@ -1185,10 +1186,11 @@ static u8 hpt3xx_cable_detect(ide_hwif_t
 		u8 scr2 = 0;
 
 		pci_read_config_byte(dev, 0x5b, &scr2);
-		pci_write_config_byte(dev, 0x5b, (scr2 & ~1));
-		/* now read cable id register */
+		pci_write_config_byte(dev, 0x5b, scr2 & ~1);
+		/* Debounce, then read cable ID register */
+		udelay(10);
 		pci_read_config_byte(dev, 0x5a, &scr1);
-		pci_write_config_byte(dev, 0x5b,  scr2);
+		pci_write_config_byte(dev, 0x5b, scr2);
 	} else
 		pci_read_config_byte(dev, 0x5a, &scr1);
 

Re: [PATCH 1/2] hpt366: add debounce delay to cable_detect() method

[David Miller]

From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Date: Mon, 27 Sep 2010 18:08:15 +0400

> Alan Cox reported that cable detection sometimes works unreliably
> for HPT3xxN and that the issue is fixed by adding debounce delay
> as used by the vendor drivers.
> 
> While at it, get rid of unneeded parens/space in the vicinity...
> 
> Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>

Applied.