diff mbox series

[6/6] i3c: master: svc: fix random hot join failure since timeout error

Message ID 20231016153232.2851095-7-Frank.Li@nxp.com (mailing list archive)
State Superseded
Headers show
Series i3c: master: svc: collection of bugs fixes | expand

Commit Message

Frank Li Oct. 16, 2023, 3:32 p.m. UTC
master side report:
  silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000

BIT 20: TIMEOUT error
  The module has stalled too long in a frame. This happens when:
  - The TX FIFO or RX FIFO is not handled and the bus is stuck in the
middle of a message,
  - No STOP was issued and between messages,
  - IBI manual is used and no decision was made.
  The maximum stall period is 10 KHz or 100 μs.

This is a just warning. System irq thread schedule latency is possible
bigger than 100us. Just omit this waring.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master/svc-i3c-master.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Miquel Raynal Oct. 17, 2023, 2:33 p.m. UTC | #1
Hi Frank,

Frank.Li@nxp.com wrote on Mon, 16 Oct 2023 11:32:32 -0400:

> master side report:
>   silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000
> 
> BIT 20: TIMEOUT error
>   The module has stalled too long in a frame. This happens when:
>   - The TX FIFO or RX FIFO is not handled and the bus is stuck in the
> middle of a message,
>   - No STOP was issued and between messages,
>   - IBI manual is used and no decision was made.
>   The maximum stall period is 10 KHz or 100 μs.
> 
> This is a just warning. System irq thread schedule latency is possible

							can be bigger
> bigger than 100us. Just omit this waring.

I'm not sure this is the correct approach. It's a real issue but there
is not much we can do about it. Perhaps dev_err is too high, but I
would not entirely drop this message. Maybe a comment and turning the
message into a dbg printk would be more appropriate?

> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/i3c/master/svc-i3c-master.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 5bca369d6912..18bc277edc8a 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -93,6 +93,7 @@
>  #define SVC_I3C_MINTMASKED   0x098
>  #define SVC_I3C_MERRWARN     0x09C
>  #define   SVC_I3C_MERRWARN_NACK BIT(2)
> +#define   SVC_I3C_MERRWARN_TIMEOUT BIT(20)
>  #define SVC_I3C_MDMACTRL     0x0A0
>  #define SVC_I3C_MDATACTRL    0x0AC
>  #define   SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
> @@ -225,6 +226,11 @@ static bool svc_i3c_master_error(struct svc_i3c_master *master)
>  	if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
>  		merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
>  		writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
> +
> +		/* ignore timeout error */
> +		if (merrwarn & SVC_I3C_MERRWARN_TIMEOUT)
> +			return false;
> +
>  		dev_err(master->dev,
>  			"Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
>  			mstatus, merrwarn);


Thanks,
Miquèl
Frank Li Oct. 17, 2023, 2:45 p.m. UTC | #2
On Tue, Oct 17, 2023 at 04:33:35PM +0200, Miquel Raynal wrote:
> Hi Frank,
> 
> Frank.Li@nxp.com wrote on Mon, 16 Oct 2023 11:32:32 -0400:
> 
> > master side report:
> >   silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000
> > 
> > BIT 20: TIMEOUT error
> >   The module has stalled too long in a frame. This happens when:
> >   - The TX FIFO or RX FIFO is not handled and the bus is stuck in the
> > middle of a message,
> >   - No STOP was issued and between messages,
> >   - IBI manual is used and no decision was made.
> >   The maximum stall period is 10 KHz or 100 μs.
> > 
> > This is a just warning. System irq thread schedule latency is possible
> 
> 							can be bigger
> > bigger than 100us. Just omit this waring.
> 
> I'm not sure this is the correct approach. It's a real issue but there
> is not much we can do about it. Perhaps dev_err is too high, but I
> would not entirely drop this message. Maybe a comment and turning the
> message into a dbg printk would be more appropriate?

The key is not message. It return true, means IBI/HJ thread will not run.

Frank

> 
> > Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> >  drivers/i3c/master/svc-i3c-master.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> > index 5bca369d6912..18bc277edc8a 100644
> > --- a/drivers/i3c/master/svc-i3c-master.c
> > +++ b/drivers/i3c/master/svc-i3c-master.c
> > @@ -93,6 +93,7 @@
> >  #define SVC_I3C_MINTMASKED   0x098
> >  #define SVC_I3C_MERRWARN     0x09C
> >  #define   SVC_I3C_MERRWARN_NACK BIT(2)
> > +#define   SVC_I3C_MERRWARN_TIMEOUT BIT(20)
> >  #define SVC_I3C_MDMACTRL     0x0A0
> >  #define SVC_I3C_MDATACTRL    0x0AC
> >  #define   SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
> > @@ -225,6 +226,11 @@ static bool svc_i3c_master_error(struct svc_i3c_master *master)
> >  	if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
> >  		merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
> >  		writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
> > +
> > +		/* ignore timeout error */
> > +		if (merrwarn & SVC_I3C_MERRWARN_TIMEOUT)
> > +			return false;
> > +
> >  		dev_err(master->dev,
> >  			"Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
> >  			mstatus, merrwarn);
> 
> 
> Thanks,
> Miquèl
Miquel Raynal Oct. 17, 2023, 3:06 p.m. UTC | #3
Hi Frank,

Frank.li@nxp.com wrote on Tue, 17 Oct 2023 10:45:14 -0400:

> On Tue, Oct 17, 2023 at 04:33:35PM +0200, Miquel Raynal wrote:
> > Hi Frank,
> > 
> > Frank.Li@nxp.com wrote on Mon, 16 Oct 2023 11:32:32 -0400:
> >   
> > > master side report:
> > >   silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000
> > > 
> > > BIT 20: TIMEOUT error
> > >   The module has stalled too long in a frame. This happens when:
> > >   - The TX FIFO or RX FIFO is not handled and the bus is stuck in the
> > > middle of a message,
> > >   - No STOP was issued and between messages,
> > >   - IBI manual is used and no decision was made.
> > >   The maximum stall period is 10 KHz or 100 μs.
> > > 
> > > This is a just warning. System irq thread schedule latency is possible  
> > 
> > 							can be bigger  
> > > bigger than 100us. Just omit this waring.  
> > 
> > I'm not sure this is the correct approach. It's a real issue but there
> > is not much we can do about it. Perhaps dev_err is too high, but I
> > would not entirely drop this message. Maybe a comment and turning the
> > message into a dbg printk would be more appropriate?  
> 
> The key is not message. It return true, means IBI/HJ thread will not run.

But why should the workers run if it's too late?

Thanks,
Miquèl
Frank Li Oct. 17, 2023, 3:25 p.m. UTC | #4
On Tue, Oct 17, 2023 at 05:06:03PM +0200, Miquel Raynal wrote:
> Hi Frank,
> 
> Frank.li@nxp.com wrote on Tue, 17 Oct 2023 10:45:14 -0400:
> 
> > On Tue, Oct 17, 2023 at 04:33:35PM +0200, Miquel Raynal wrote:
> > > Hi Frank,
> > > 
> > > Frank.Li@nxp.com wrote on Mon, 16 Oct 2023 11:32:32 -0400:
> > >   
> > > > master side report:
> > > >   silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000
> > > > 
> > > > BIT 20: TIMEOUT error
> > > >   The module has stalled too long in a frame. This happens when:
> > > >   - The TX FIFO or RX FIFO is not handled and the bus is stuck in the
> > > > middle of a message,
> > > >   - No STOP was issued and between messages,
> > > >   - IBI manual is used and no decision was made.
> > > >   The maximum stall period is 10 KHz or 100 μs.
> > > > 
> > > > This is a just warning. System irq thread schedule latency is possible  
> > > 
> > > 							can be bigger  
> > > > bigger than 100us. Just omit this waring.  
> > > 
> > > I'm not sure this is the correct approach. It's a real issue but there
> > > is not much we can do about it. Perhaps dev_err is too high, but I
> > > would not entirely drop this message. Maybe a comment and turning the
> > > message into a dbg printk would be more appropriate?  
> > 
> > The key is not message. It return true, means IBI/HJ thread will not run.
> 
> But why should the workers run if it's too late?

IBI ACK already sent, target think master already accepted IBI. then master
driver check TIMEOUT, 

If without run IBI thread, target's driver will wait target sent IBI. And
target wait for driver handle IBI. 

So the whole system may lock or wait for long time out.

Hardware check TIMEOUT and software send ACK is totally async.

> 
> Thanks,
> Miquèl
diff mbox series

Patch

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 5bca369d6912..18bc277edc8a 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -93,6 +93,7 @@ 
 #define SVC_I3C_MINTMASKED   0x098
 #define SVC_I3C_MERRWARN     0x09C
 #define   SVC_I3C_MERRWARN_NACK BIT(2)
+#define   SVC_I3C_MERRWARN_TIMEOUT BIT(20)
 #define SVC_I3C_MDMACTRL     0x0A0
 #define SVC_I3C_MDATACTRL    0x0AC
 #define   SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
@@ -225,6 +226,11 @@  static bool svc_i3c_master_error(struct svc_i3c_master *master)
 	if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
 		merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
 		writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
+
+		/* ignore timeout error */
+		if (merrwarn & SVC_I3C_MERRWARN_TIMEOUT)
+			return false;
+
 		dev_err(master->dev,
 			"Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
 			mstatus, merrwarn);