PROBLEM: incorrect interrupt ack lead to interrupt loss on freescale powerpc

[Li Yang-R58472]

> -----Original Message-----
> From: dayu at datangmobile.cn [mailto:dayu at datangmobile.cn] 
> Sent: Tuesday, February 17, 2009 4:34 PM
> To: linux-kernel at vger.kernel.org
> Cc: Li Yang-R58472
> Subject: PROBLEM: incorrect interrupt ack lead to interrupt 
> loss on freescale powerpc
> 
>  
> [1.] One line summary of the problem: incorrect interrupt ack 
>  lead to interrupt loss

Acked-by: Li Yang <leoli at freescale.com>

However, please resend the patch with a brief description and Signed-off-by at the top of the patch.  You can read the Documentation/SubmittiongPatches for more information, or even a Chinese version under Documentation/zh_CN/.

Here are some small comments about the patch itself,

--- a/arch/powerpc/sysdev/ipic.c	2009-02-17 15:10:18.000000000 +0800
+++ b/arch/powerpc/sysdev/ipic.c	2009-02-17 15:10:24.000000000 +0800
@@ -9,6 +9,7 @@
  * under  the terms of  the GNU General  Public License as published by the
  * Free Software Foundation;  either version 2 of the  License, or (at your
  * option) any later version.
+ * Da Yu <dayu at datangmobile.cn> fixed the interrupt loss problem on powerpc IPIC


It's not recommended to add changelog in the source now.  Please describe in the patch description area.

  */
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -561,8 +562,7 @@
 
 	spin_lock_irqsave(&ipic_lock, flags);
 
-	temp = ipic_read(ipic->regs, ipic_info[src].pend);
-	temp |= (1 << (31 - ipic_info[src].bit));
+	temp = (1 << (31 - ipic_info[src].bit));


Remove unneeded brackets.


 	ipic_write(ipic->regs, ipic_info[src].pend, temp);
 
 	spin_unlock_irqrestore(&ipic_lock, flags);
@@ -581,8 +581,7 @@
 	temp &= ~(1 << (31 - ipic_info[src].bit));
 	ipic_write(ipic->regs, ipic_info[src].mask, temp);
 
-	temp = ipic_read(ipic->regs, ipic_info[src].pend);
-	temp |= (1 << (31 - ipic_info[src].bit));
+	temp = (1 << (31 - ipic_info[src].bit));

Same as above.


 	ipic_write(ipic->regs, ipic_info[src].pend, temp);
 
 	spin_unlock_irqrestore(&ipic_lock, flags);