| Message ID | D728AD1FA2543948B89DE29C5BF4CD0716AC2DDE@bjmail1.bj.datangmobile.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, Feb 17, 2009 at 10:12 PM, Kumar Gala <galak@kernel.crashing.org> wrote: > > On Feb 17, 2009, at 6:44 AM, <dayu@datangmobile.cn> <dayu@datangmobile.cn> > wrote: > >> From: Da Yu <dayu@datangmobile.cn> >> Date: Tue, 17 Feb 2009 19:58:20 +0800 >> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC (2.6.23) >> >> Signed-off-by: Da Yu <dayu@datangmobile.cn> >> --- > > Please provide a bit more description as to why this fixes the issue. The pending register is write 1 clear. If there are more than one external interrupts pending at the same time, acking the first interrupt will also clear other interrupt pending bits. That will cause loss of interrupt. - Leo
On Feb 17, 2009, at 8:38 AM, Li Yang wrote: > On Tue, Feb 17, 2009 at 10:12 PM, Kumar Gala <galak@kernel.crashing.org > > wrote: >> >> On Feb 17, 2009, at 6:44 AM, <dayu@datangmobile.cn> <dayu@datangmobile.cn >> > >> wrote: >> >>> From: Da Yu <dayu@datangmobile.cn> >>> Date: Tue, 17 Feb 2009 19:58:20 +0800 >>> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC >>> (2.6.23) >>> >>> Signed-off-by: Da Yu <dayu@datangmobile.cn> >>> --- >> >> Please provide a bit more description as to why this fixes the issue. > > The pending register is write 1 clear. If there are more than one > external interrupts pending at the same time, acking the first > interrupt will also clear other interrupt pending bits. That will > cause loss of interrupt. > > - Leo Thanks. That should be included in the commit message. - k
On Tue, Feb 17, 2009 at 10:32 PM, Josh Boyer <jwboyer@linux.vnet.ibm.com> wrote: > On Tue, Feb 17, 2009 at 08:12:33AM -0600, Kumar Gala wrote: >> >> On Feb 17, 2009, at 6:44 AM, <dayu@datangmobile.cn> <dayu@datangmobile.cn >> > wrote: >> >>> From: Da Yu <dayu@datangmobile.cn> >>> Date: Tue, 17 Feb 2009 19:58:20 +0800 >>> Subject: [PATCH] fix the interrupt loss problem on powerpc IPIC >>> (2.6.23) >>> >>> Signed-off-by: Da Yu <dayu@datangmobile.cn> >>> --- >> >> Please provide a bit more description as to why this fixes the issue. > > Including whether it still applies to mainline, since your topic seems > to indicate it's for 2.6.23. That is pretty old by now. The problem still exists in mainline. But the patch doesn't seem to apply. Dayu, Could you re-spin the patch for the latest kernel? Thanks. - Leo
--- a/arch/powerpc/sysdev/ipic.c 2009-02-17 15:10:18.000000000 +0800 +++ b/arch/powerpc/sysdev/ipic.c 2009-02-17 20:05:28.000000000 +0800 @@ -561,8 +561,7 @@ static void ipic_ack_irq(unsigned int vi 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); ipic_write(ipic->regs, ipic_info[src].pend, temp); spin_unlock_irqrestore(&ipic_lock, flags); @@ -581,8 +580,7 @@ static void ipic_mask_irq_and_ack(unsign 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); ipic_write(ipic->regs, ipic_info[src].pend, temp); spin_unlock_irqrestore(&ipic_lock, flags); -----邮件原件----- 发件人: Li Yang-R58472 [mailto:LeoLi@freescale.com] 发送时间: 2009年2月17日 18:17 收件人: 笪禹; linux-kernel@vger.kernel.org 抄送: linuxppc-dev@ozlabs.org 主题: RE: PROBLEM: incorrect interrupt ack lead to interrupt loss on freescale powerpc > -----Original Message----- > From: dayu@datangmobile.cn [mailto:dayu@datangmobile.cn] > Sent: Tuesday, February 17, 2009 4:34 PM > To: linux-kernel@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@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@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.