[PATCH 1/15] ali14xx: fix deadlock on error handling

[PATCH 1/15] ali14xx: fix deadlock on error handling

[Bartlomiej Zolnierkiewicz]

Stop abusing ide_lock lock by switching to a private locking.

Fixes same issue as fixed by Alan Cox in atiixp host driver with
commit 6c5f8cc33eb2e10b6ab788bbe259fc142a068627.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
 drivers/ide/legacy/ali14xx.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Index: b/drivers/ide/legacy/ali14xx.c
===================================================================
--- a/drivers/ide/legacy/ali14xx.c
+++ b/drivers/ide/legacy/ali14xx.c
@@ -102,6 +102,8 @@ static void outReg (u8 data, u8 reg)
 	outb_p(data, dataPort);
 }
 
+static DEFINE_SPINLOCK(ali14xx_lock);
+
 /*
  * Set PIO mode for the specified drive.
  * This function computes timing parameters
@@ -129,14 +131,14 @@ static void ali14xx_set_pio_mode(ide_dri
 
 	/* stuff timing parameters into controller registers */
 	driveNum = (HWIF(drive)->index << 1) + drive->select.b.unit;
-	spin_lock_irqsave(&ide_lock, flags);
+	spin_lock_irqsave(&ali14xx_lock, flags);
 	outb_p(regOn, basePort);
 	outReg(param1, regTab[driveNum].reg1);
 	outReg(param2, regTab[driveNum].reg2);
 	outReg(param3, regTab[driveNum].reg3);
 	outReg(param4, regTab[driveNum].reg4);
 	outb_p(regOff, basePort);
-	spin_unlock_irqrestore(&ide_lock, flags);
+	spin_unlock_irqrestore(&ali14xx_lock, flags);
 }
 
 /*

Re: [PATCH 1/15] ali14xx: fix deadlock on error handling

[Sergei Shtylyov]

Bartlomiej Zolnierkiewicz wrote:

> Stop abusing ide_lock lock by switching to a private locking.

> Fixes same issue as fixed by Alan Cox in atiixp host driver with

    Has been also fixed in the piix driver.

> commit 6c5f8cc33eb2e10b6ab788bbe259fc142a068627.

    Heh, I've looked hard at the code trying to understand how this can 
happen, and was unable to figure out. Probably was not hard enough...

> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>

MBR, Sergei

Re: [PATCH 1/15] ali14xx: fix deadlock on error handling

[Alan Cox]

On Tue, 02 Oct 2007 16:46:28 +0400
Sergei Shtylyov <sshtylyov@ru.mvista.com> wrote:

> Bartlomiej Zolnierkiewicz wrote:
> 
> > Stop abusing ide_lock lock by switching to a private locking.
> 
> > Fixes same issue as fixed by Alan Cox in atiixp host driver with
> 
>     Has been also fixed in the piix driver.
> 
> > commit 6c5f8cc33eb2e10b6ab788bbe259fc142a068627.
> 
>     Heh, I've looked hard at the code trying to understand how this can 
> happen, and was unable to figure out. Probably was not hard enough...

The old IDE code timer, error handling and interrupt paths all race each
other. Anything can happen including this.

The proper fix is to rewrite the error handling but it was easier to port
the drivers to working error handling instead - hence libata PATA

Alan