[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[Tommy Huang]

When the i2c bus recovey occurs, driver will send i2c stop command
in the scl low condition. In this case the sw state will still keep
original situation. Under multi-master usage, i2c bus recovery will
be called when i2c transfer timeout occurs. Update the stop command
calling with aspeed_i2c_do_stop function to update master_state.

Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C")

Signed-off-by: Tommy Huang <tommy_huang@aspeedtech.com>
---
 drivers/i2c/busses/i2c-aspeed.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index ce8c4846b7fa..32f8b0c1c174 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -169,6 +169,7 @@ struct aspeed_i2c_bus {
 };
 
 static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
+static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus);
 
 static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
 {
@@ -187,7 +188,7 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
 			command);
 
 		reinit_completion(&bus->cmd_complete);
-		writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG);
+		aspeed_i2c_do_stop(bus);
 		spin_unlock_irqrestore(&bus->lock, flags);
 
 		time_left = wait_for_completion_timeout(
-- 
2.25.1

[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[Paul Menzel]

Dear Tommy,


Thank you for your patch.

Am 30.05.24 um 09:06 schrieb Tommy Huang:
> When the i2c bus recovey occurs, driver will send i2c stop command

recove*r*y

> in the scl low condition. In this case the sw state will still keep
> original situation. Under multi-master usage, i2c bus recovery will

What is the user visible problem?

> be called when i2c transfer timeout occurs. Update the stop command
> calling with aspeed_i2c_do_stop function to update master_state.

How can this be tested?

> Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C")
> 

The blank line can be removed.

> Signed-off-by: Tommy Huang <tommy_huang@aspeedtech.com>
> ---
>   drivers/i2c/busses/i2c-aspeed.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
> index ce8c4846b7fa..32f8b0c1c174 100644
> --- a/drivers/i2c/busses/i2c-aspeed.c
> +++ b/drivers/i2c/busses/i2c-aspeed.c
> @@ -169,6 +169,7 @@ struct aspeed_i2c_bus {
>   };
>   
>   static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
> +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus);
>   
>   static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
>   {
> @@ -187,7 +188,7 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
>   			command);
>   
>   		reinit_completion(&bus->cmd_complete);
> -		writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG);
> +		aspeed_i2c_do_stop(bus);
>   		spin_unlock_irqrestore(&bus->lock, flags);
>   
>   		time_left = wait_for_completion_timeout(


Kind regards,

Paul

[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[Tommy Huang]

Hi Paul,

	Thanks for your comments.

> -----Original Message-----
> From: Paul Menzel <pmenzel@molgen.mpg.de>
> Sent: Thursday, May 30, 2024 3:48 PM
> To: Tommy Huang <tommy_huang@aspeedtech.com>
> Cc: brendan.higgins at linux.dev; benh at kernel.crashing.org; joel at jms.id.au;
> andi.shyti at kernel.org; andrew at codeconstruct.com.au; wsa at kernel.org;
> BMC-SW <BMC-SW@aspeedtech.com>; linux-aspeed at lists.ozlabs.org;
> openbmc at lists.ozlabs.org; linux-kernel at vger.kernel.org;
> linux-i2c at vger.kernel.org; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH] i2c: aspeed: Update the stop sw state when the bus
> recovry occurs
> 
> Dear Tommy,
> 
> 
> Thank you for your patch.
> 
> Am 30.05.24 um 09:06 schrieb Tommy Huang:
> > When the i2c bus recovey occurs, driver will send i2c stop command
> 
> recove*r*y

I will fix this spelling typo on next patch. Thanks.

> 
> > in the scl low condition. In this case the sw state will still keep
> > original situation. Under multi-master usage, i2c bus recovery will
> 
> What is the user visible problem?
> 

In the multi-master case, the i2c transfer timeout will execute the aspeed_i2c_recover_bus.
What we noticed when timeout appears, and kernel panic is observed:
-	xfer goes through aspeed_i2c_recovery_bus 
-	inside recovery we can see ?SCL hung (state ec0b0000), attempting recovery?. 
-	STOP_CMD is performed but time_left = 0 what causes that aspeed_i2c_reset is called (and returns 0)
-	Going out of timeout handling, release memory, irq handler is invoked and rise interrupt causing that released memory is used.

> > be called when i2c transfer timeout occurs. Update the stop command
> > calling with aspeed_i2c_do_stop function to update master_state.
> 
> How can this be tested?

It just updates master_state for usage safety. The original stop command still be triggered.
> 
> > Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C")
> >
> 
> The blank line can be removed.
> 
> > Signed-off-by: Tommy Huang <tommy_huang@aspeedtech.com>
> > ---
> >   drivers/i2c/busses/i2c-aspeed.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-aspeed.c
> > b/drivers/i2c/busses/i2c-aspeed.c index ce8c4846b7fa..32f8b0c1c174
> > 100644
> > --- a/drivers/i2c/busses/i2c-aspeed.c
> > +++ b/drivers/i2c/busses/i2c-aspeed.c
> > @@ -169,6 +169,7 @@ struct aspeed_i2c_bus {
> >   };
> >
> >   static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
> > +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus);
> >
> >   static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
> >   {
> > @@ -187,7 +188,7 @@ static int aspeed_i2c_recover_bus(struct
> aspeed_i2c_bus *bus)
> >   			command);
> >
> >   		reinit_completion(&bus->cmd_complete);
> > -		writel(ASPEED_I2CD_M_STOP_CMD, bus->base +
> ASPEED_I2C_CMD_REG);
> > +		aspeed_i2c_do_stop(bus);
> >   		spin_unlock_irqrestore(&bus->lock, flags);
> >
> >   		time_left = wait_for_completion_timeout(
> 
> 
> Kind regards,
> 
> Paul

BR,

Tommy

[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[Andi Shyti]

Hi Tommy,

On Thu, May 30, 2024 at 03:06:56PM +0800, Tommy Huang wrote:
> When the i2c bus recovey occurs, driver will send i2c stop command
> in the scl low condition. In this case the sw state will still keep
> original situation. Under multi-master usage, i2c bus recovery will
> be called when i2c transfer timeout occurs. Update the stop command
> calling with aspeed_i2c_do_stop function to update master_state.
> 
> Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C")
> 
> Signed-off-by: Tommy Huang <tommy_huang@aspeedtech.com>

Can you please add:

Cc: <stable@vger.kernel.org> # v4.13+

> ---
>  drivers/i2c/busses/i2c-aspeed.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
> index ce8c4846b7fa..32f8b0c1c174 100644
> --- a/drivers/i2c/busses/i2c-aspeed.c
> +++ b/drivers/i2c/busses/i2c-aspeed.c
> @@ -169,6 +169,7 @@ struct aspeed_i2c_bus {
>  };
>  
>  static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
> +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus);

Can you please move aspeed_i2c_do_stop() on top? Doesn't make
much sense to add the prototype here as there is no dependencies.

It's different the case of aspeed_i2c_reset() because it needs
aspeed_i2c_init().

>  static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
>  {
> @@ -187,7 +188,7 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
>  			command);
>  
>  		reinit_completion(&bus->cmd_complete);
> -		writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG);
> +		aspeed_i2c_do_stop(bus);

The patch is good, though!

Thanks,
Andi

[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[Tommy Huang]

Hi Andi,

> -----Original Message-----
> From: Andi Shyti <andi.shyti@kernel.org>
> Sent: Thursday, June 6, 2024 9:27 AM
> To: Tommy Huang <tommy_huang@aspeedtech.com>
> Cc: brendan.higgins at linux.dev; benh at kernel.crashing.org; joel at jms.id.au;
> andrew at codeconstruct.com.au; wsa at kernel.org; linux-i2c at vger.kernel.org;
> openbmc at lists.ozlabs.org; linux-arm-kernel at lists.infradead.org;
> linux-aspeed at lists.ozlabs.org; linux-kernel at vger.kernel.org; BMC-SW
> <BMC-SW@aspeedtech.com>
> Subject: Re: [PATCH] i2c: aspeed: Update the stop sw state when the bus
> recovry occurs
> 
> Hi Tommy,
> 
> On Thu, May 30, 2024 at 03:06:56PM +0800, Tommy Huang wrote:
> > When the i2c bus recovey occurs, driver will send i2c stop command in
> > the scl low condition. In this case the sw state will still keep
> > original situation. Under multi-master usage, i2c bus recovery will be
> > called when i2c transfer timeout occurs. Update the stop command
> > calling with aspeed_i2c_do_stop function to update master_state.
> >
> > Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C")
> >
> > Signed-off-by: Tommy Huang <tommy_huang@aspeedtech.com>
> 
> Can you please add:
> 
> Cc: <stable@vger.kernel.org> # v4.13+

Got it. I will add it.

> 
> > ---
> >  drivers/i2c/busses/i2c-aspeed.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-aspeed.c
> > b/drivers/i2c/busses/i2c-aspeed.c index ce8c4846b7fa..32f8b0c1c174
> > 100644
> > --- a/drivers/i2c/busses/i2c-aspeed.c
> > +++ b/drivers/i2c/busses/i2c-aspeed.c
> > @@ -169,6 +169,7 @@ struct aspeed_i2c_bus {  };
> >
> >  static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
> > +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus);
> 
> Can you please move aspeed_i2c_do_stop() on top? Doesn't make much sense
> to add the prototype here as there is no dependencies.

Sure. I will update it.

> 
> It's different the case of aspeed_i2c_reset() because it needs aspeed_i2c_init().
> 
> >  static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)  { @@
> > -187,7 +188,7 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus
> *bus)
> >  			command);
> >
> >  		reinit_completion(&bus->cmd_complete);
> > -		writel(ASPEED_I2CD_M_STOP_CMD, bus->base +
> ASPEED_I2C_CMD_REG);
> > +		aspeed_i2c_do_stop(bus);
> 
> The patch is good, though!
> 

Thanks for your commects.

> Thanks,
> Andi

[PATCH] i2c: aspeed: Update the stop sw state when the bus recovry occurs

[Tommy Huang]

Hi Andi,

	There is a problem to move aspeed_i2c_do_stop() on top.
	This function is like with aspeed_i2c_reset function needs the aspeed_i2c_bus structure definition.

	BR,

	By Tommy

> -----Original Message-----
> From: Tommy Huang <tommy_huang@aspeedtech.com>
> Sent: Saturday, June 8, 2024 12:38 PM
> To: Andi Shyti <andi.shyti@kernel.org>
> Cc: brendan.higgins at linux.dev; benh at kernel.crashing.org; joel at jms.id.au;
> andrew at codeconstruct.com.au; wsa at kernel.org; linux-i2c at vger.kernel.org;
> openbmc at lists.ozlabs.org; linux-arm-kernel at lists.infradead.org;
> linux-aspeed at lists.ozlabs.org; linux-kernel at vger.kernel.org; BMC-SW
> <BMC-SW@aspeedtech.com>
> Subject: RE: [PATCH] i2c: aspeed: Update the stop sw state when the bus
> recovry occurs
> 
> Hi Andi,
> 
> > -----Original Message-----
> > From: Andi Shyti <andi.shyti@kernel.org>
> > Sent: Thursday, June 6, 2024 9:27 AM
> > To: Tommy Huang <tommy_huang@aspeedtech.com>
> > Cc: brendan.higgins at linux.dev; benh at kernel.crashing.org;
> > joel at jms.id.au; andrew at codeconstruct.com.au; wsa at kernel.org;
> > linux-i2c at vger.kernel.org; openbmc at lists.ozlabs.org;
> > linux-arm-kernel at lists.infradead.org;
> > linux-aspeed at lists.ozlabs.org; linux-kernel at vger.kernel.org; BMC-SW
> > <BMC-SW@aspeedtech.com>
> > Subject: Re: [PATCH] i2c: aspeed: Update the stop sw state when the
> > bus recovry occurs
> >
> > Hi Tommy,
> >
> > On Thu, May 30, 2024 at 03:06:56PM +0800, Tommy Huang wrote:
> > > When the i2c bus recovey occurs, driver will send i2c stop command
> > > in the scl low condition. In this case the sw state will still keep
> > > original situation. Under multi-master usage, i2c bus recovery will
> > > be called when i2c transfer timeout occurs. Update the stop command
> > > calling with aspeed_i2c_do_stop function to update master_state.
> > >
> > > Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C")
> > >
> > > Signed-off-by: Tommy Huang <tommy_huang@aspeedtech.com>
> >
> > Can you please add:
> >
> > Cc: <stable@vger.kernel.org> # v4.13+
> 
> Got it. I will add it.
> 
> >
> > > ---
> > >  drivers/i2c/busses/i2c-aspeed.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/i2c/busses/i2c-aspeed.c
> > > b/drivers/i2c/busses/i2c-aspeed.c index ce8c4846b7fa..32f8b0c1c174
> > > 100644
> > > --- a/drivers/i2c/busses/i2c-aspeed.c
> > > +++ b/drivers/i2c/busses/i2c-aspeed.c
> > > @@ -169,6 +169,7 @@ struct aspeed_i2c_bus {  };
> > >
> > >  static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus);
> > > +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus);
> >
> > Can you please move aspeed_i2c_do_stop() on top? Doesn't make much
> > sense to add the prototype here as there is no dependencies.
> 
> Sure. I will update it.
> 
> >
> > It's different the case of aspeed_i2c_reset() because it needs
> aspeed_i2c_init().
> >
> > >  static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)  { @@
> > > -187,7 +188,7 @@ static int aspeed_i2c_recover_bus(struct
> > > aspeed_i2c_bus
> > *bus)
> > >  			command);
> > >
> > >  		reinit_completion(&bus->cmd_complete);
> > > -		writel(ASPEED_I2CD_M_STOP_CMD, bus->base +
> > ASPEED_I2C_CMD_REG);
> > > +		aspeed_i2c_do_stop(bus);
> >
> > The patch is good, though!
> >
> 
> Thanks for your commects.
> 
> > Thanks,
> > Andi