[PATCH] mmc: mmcif: don't clear masked interrupts

[PATCH] mmc: mmcif: don't clear masked interrupts

[Guennadi Liakhovetski]

Masking events on MMCIF means, an occurrence of the masked event won't raise
an interrupt, but the event bit will still be set in the interrupt status
register. If simultaneously a different event occurs, that was enabled, both
flags will be set. However, only the unmasked event bit should be cleared in
the status register in such a case. Clearing also the masked bit can lead to
lost interrupts, which indeed can be observed on the armadillo800eva r8a7740
board with an eMMC chip. The problem has been introduced by the recent "mmc:
sh_mmcif: simplify IRQ processing" patch. Fix the problem by only clearing
enabled interrupts.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
---

Chris, please, push this fix to 3.10, thanks.

 drivers/mmc/host/sh_mmcif.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index ba76a53..06caaae 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -1244,7 +1244,8 @@ static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
 	u32 state;
 
 	state = sh_mmcif_readl(host->addr, MMCIF_CE_INT);
-	sh_mmcif_writel(host->addr, MMCIF_CE_INT, ~state);
+	sh_mmcif_writel(host->addr, MMCIF_CE_INT,
+			~(state & sh_mmcif_readl(host->addr, MMCIF_CE_INT_MASK)));
 	sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state & MASK_CLEAN);
 
 	if (state & ~MASK_CLEAN)
-- 
1.7.2.5

Re: [PATCH] mmc: mmcif: don't clear masked interrupts

[Guennadi Liakhovetski]

On Wed, 15 May 2013, Guennadi Liakhovetski wrote:

> Masking events on MMCIF means, an occurrence of the masked event won't raise
> an interrupt, but the event bit will still be set in the interrupt status
> register. If simultaneously a different event occurs, that was enabled, both
> flags will be set. However, only the unmasked event bit should be cleared in
> the status register in such a case. Clearing also the masked bit can lead to
> lost interrupts, which indeed can be observed on the armadillo800eva r8a7740
> board with an eMMC chip. The problem has been introduced by the recent "mmc:
> sh_mmcif: simplify IRQ processing" patch. Fix the problem by only clearing
> enabled interrupts.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>

Sorry, forgot to add a

Reported-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>

Thanks
Guennadi

> ---
> 
> Chris, please, push this fix to 3.10, thanks.
> 
>  drivers/mmc/host/sh_mmcif.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
> index ba76a53..06caaae 100644
> --- a/drivers/mmc/host/sh_mmcif.c
> +++ b/drivers/mmc/host/sh_mmcif.c
> @@ -1244,7 +1244,8 @@ static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
>  	u32 state;
>  
>  	state = sh_mmcif_readl(host->addr, MMCIF_CE_INT);
> -	sh_mmcif_writel(host->addr, MMCIF_CE_INT, ~state);
> +	sh_mmcif_writel(host->addr, MMCIF_CE_INT,
> +			~(state & sh_mmcif_readl(host->addr, MMCIF_CE_INT_MASK)));
>  	sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state & MASK_CLEAN);
>  
>  	if (state & ~MASK_CLEAN)
> -- 
> 1.7.2.5
> 
> --
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> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [PATCH] mmc: mmcif: don't clear masked interrupts

[Nguyen Viet Dung]

On 05/15/2013 02:50 PM, Guennadi Liakhovetski wrote:
> Masking events on MMCIF means, an occurrence of the masked event won't raise
> an interrupt, but the event bit will still be set in the interrupt status
> register. If simultaneously a different event occurs, that was enabled, both
> flags will be set. However, only the unmasked event bit should be cleared in
> the status register in such a case. Clearing also the masked bit can lead to
> lost interrupts, which indeed can be observed on the armadillo800eva r8a7740
> board with an eMMC chip. The problem has been introduced by the recent "mmc:
> sh_mmcif: simplify IRQ processing" patch. Fix the problem by only clearing
> enabled interrupts.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>

tested-by: Nguyen Viet Dung<nv-dung@jinso.co.jp>

Best regards
Nguyen Viet Dung

> ---
>
> Chris, please, push this fix to 3.10, thanks.
>
>   drivers/mmc/host/sh_mmcif.c |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
> index ba76a53..06caaae 100644
> --- a/drivers/mmc/host/sh_mmcif.c
> +++ b/drivers/mmc/host/sh_mmcif.c
> @@ -1244,7 +1244,8 @@ static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
>   	u32 state;
>   
>   	state = sh_mmcif_readl(host->addr, MMCIF_CE_INT);
> -	sh_mmcif_writel(host->addr, MMCIF_CE_INT, ~state);
> +	sh_mmcif_writel(host->addr, MMCIF_CE_INT,
> +			~(state & sh_mmcif_readl(host->addr, MMCIF_CE_INT_MASK)));
>   	sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state & MASK_CLEAN);
>   
>   	if (state & ~MASK_CLEAN)

Re: [PATCH] mmc: mmcif: don't clear masked interrupts

[Kuninori Morimoto]

Hi
At Wed, 15 May 2013 17:39:23 +0900,
Nguyen Viet Dung wrote:
> 
> On 05/15/2013 02:50 PM, Guennadi Liakhovetski wrote:
> > Masking events on MMCIF means, an occurrence of the masked event won't raise
> > an interrupt, but the event bit will still be set in the interrupt status
> > register. If simultaneously a different event occurs, that was enabled, both
> > flags will be set. However, only the unmasked event bit should be cleared in
> > the status register in such a case. Clearing also the masked bit can lead to
> > lost interrupts, which indeed can be observed on the armadillo800eva r8a7740
> > board with an eMMC chip. The problem has been introduced by the recent "mmc:
> > sh_mmcif: simplify IRQ processing" patch. Fix the problem by only clearing
> > enabled interrupts.
> >
> > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
> 
> tested-by: Nguyen Viet Dung<nv-dung@jinso.co.jp>

on Bock-W board

Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Best regards
---
Kuninori Morimoto

Re: [PATCH] mmc: mmcif: don't clear masked interrupts

[Guennadi Liakhovetski]

Hi Chris

On Wed, 15 May 2013, Kuninori Morimoto wrote:

> Hi
> At Wed, 15 May 2013 17:39:23 +0900,
> Nguyen Viet Dung wrote:
> > 
> > On 05/15/2013 02:50 PM, Guennadi Liakhovetski wrote:
> > > Masking events on MMCIF means, an occurrence of the masked event won't raise
> > > an interrupt, but the event bit will still be set in the interrupt status
> > > register. If simultaneously a different event occurs, that was enabled, both
> > > flags will be set. However, only the unmasked event bit should be cleared in
> > > the status register in such a case. Clearing also the masked bit can lead to
> > > lost interrupts, which indeed can be observed on the armadillo800eva r8a7740
> > > board with an eMMC chip. The problem has been introduced by the recent "mmc:
> > > sh_mmcif: simplify IRQ processing" patch. Fix the problem by only clearing
> > > enabled interrupts.
> > >
> > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
> > 
> > tested-by: Nguyen Viet Dung<nv-dung@jinso.co.jp>
> 
> on Bock-W board
> 
> Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Here's one more for you.

Thanks
Guennadi

> Best regards
> ---
> Kuninori Morimoto
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: [PATCH] mmc: mmcif: don't clear masked interrupts

[Chris Ball]

Hi,

On Thu, Jun 06 2013, Guennadi Liakhovetski wrote:
>> > tested-by: Nguyen Viet Dung<nv-dung@jinso.co.jp>
>> 
>> on Bock-W board
>> 
>> Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
>
> Here's one more for you.

Pushed to mmc-next for 3.10, thanks.

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child