> -----Original Message-----
> From: Quan Nguyen <[email protected]>
> Sent: Thursday, May 20, 2021 10:10 PM
> To: Ryan Chen <[email protected]>; Corey Minyard
> <[email protected]>; Rob Herring <[email protected]>; Joel Stanley
> <[email protected]>; Andrew Jeffery <[email protected]>; Brendan Higgins
> <[email protected]>; Benjamin Herrenschmidt
> <[email protected]>; Wolfram Sang <[email protected]>; Philipp Zabel
> <[email protected]>; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]
> Cc: Open Source Submission <[email protected]>; Thang Q .
> Nguyen <[email protected]>; Phong Vo
> <[email protected]>; [email protected]
> Subject: Re: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
> 
> On 20/05/2021 18:06, Ryan Chen wrote:
> >> -----Original Message-----
> >> From: openbmc
> >> <[email protected]> On
> Behalf
> >> Of Quan Nguyen
> >> Sent: Wednesday, May 19, 2021 3:50 PM
> >> To: Corey Minyard <[email protected]>; Rob Herring
> >> <[email protected]>; Joel Stanley <[email protected]>; Andrew Jeffery
> >> <[email protected]>; Brendan Higgins <[email protected]>;
> >> Benjamin Herrenschmidt <[email protected]>; Wolfram Sang
> >> <[email protected]>; Philipp Zabel <[email protected]>;
> >> [email protected];
> >> [email protected]; [email protected];
> >> [email protected]; [email protected];
> >> [email protected]
> >> Cc: Open Source Submission <[email protected]>; Thang Q .
> >> Nguyen <[email protected]>; Phong Vo
> >> <[email protected]>; [email protected]
> >> Subject: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
> >>
> >> Slave i2c device on AST2500 received a lot of slave irq while it is
> >> busy processing the response. To handle this case, adds and exports
> >> aspeed_set_slave_busy() for controller to temporary stop slave irq
> >> while slave is handling the response, and re-enable them again when the
> response is ready.
> >>
> >> Signed-off-by: Quan Nguyen <[email protected]>
> >> ---
> >> v3:
> >>    + First introduce in v3 [Quan]
> >>
> >>   drivers/i2c/busses/i2c-aspeed.c | 20 ++++++++++++++++++++
> >>   1 file changed, 20 insertions(+)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-aspeed.c
> >> b/drivers/i2c/busses/i2c-aspeed.c index b2e9c8f0ddf7..9926d04831a2
> >> 100644
> >> --- a/drivers/i2c/busses/i2c-aspeed.c
> >> +++ b/drivers/i2c/busses/i2c-aspeed.c
> >> @@ -944,6 +944,26 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus
> >> *bus,
> >>    return 0;
> >>   }
> >>
> >> +#if IS_ENABLED(CONFIG_I2C_SLAVE)
> >> +void aspeed_set_slave_busy(struct i2c_adapter *adap, bool busy) {
> >> +  struct aspeed_i2c_bus *bus = i2c_get_adapdata(adap);
> >> +  unsigned long current_mask, flags;
> >> +
> >> +  spin_lock_irqsave(&bus->lock, flags);
> >> +
> >> +  current_mask = readl(bus->base + ASPEED_I2C_INTR_CTRL_REG);
> >> +  if (busy)
> >> +          current_mask &= ~(ASPEED_I2CD_INTR_RX_DONE |
> >> ASPEED_I2CD_INTR_SLAVE_MATCH);
> >> +  else
> >> +          current_mask |= ASPEED_I2CD_INTR_RX_DONE |
> >> ASPEED_I2CD_INTR_SLAVE_MATCH;
> >> +  writel(current_mask, bus->base + ASPEED_I2C_INTR_CTRL_REG);
> >> +
> >> +  spin_unlock_irqrestore(&bus->lock, flags); }
> >> +EXPORT_SYMBOL_GPL(aspeed_set_slave_busy);
> >> +#endif
> >> +
> >>   static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus)  {
> >>    struct platform_device *pdev = to_platform_device(bus->dev);
> >> --
> >> 2.28.0
> >
> > Hello,
> >     The better idea is use disable i2c slave mode.
> >     Due to if i2c controller running in slave will get slave match, and 
> > latch the
> SCL.
> >     Until cpu clear interrupt status.
> > Ryan
> >
> Thanks Ryan,
> 
> Do you mean to enable/disable slave function as per example code below ?
Yes. it is.
> 
>          /* Turn on slave mode. */
>          func_ctrl_reg_val = readl(bus->base +
> ASPEED_I2C_FUN_CTRL_REG);
>          func_ctrl_reg_val |= ASPEED_I2CD_SLAVE_EN;
>          writel(func_ctrl_reg_val, bus->base +
> ASPEED_I2C_FUN_CTRL_REG);
> 
> Will try this idea.
> - Quan

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