From: Tyrone Ting <kfting@nuvoton.com>

From: Tyrone Ting <kfting@nuvoton.com>

Store the client address earlier since it might get called in
the i2c_recover_bus logic flow at the early stage of the func()
npcm_i2c_master_xfer.

Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Tali Perry <tali.perry1@gmail.com>
---
 drivers/i2c/busses/i2c-npcm7xx.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index 68f3d47323ab..248835220c86 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -2155,6 +2155,18 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 
 	} while (time_is_after_jiffies(time_left) && bus_busy);
 
+	/*
+	 * Previously, the address was stored w/o left-shift by one bit and
+	 * with that shift in the following call to npcm_i2c_master_start_xmit.
+	 *
+	 * Since there are cases that the i2c_recover_bus gets called at the
+	 * early stage of the func() npcm_i2c_master_xfer, the address is
+	 * stored with the shift and used in the i2c_recover_bus call.
+	 *
+	 * The address is stored from bit 1 to bit 7 in the register for
+	 * sending the i2c address later so it's left-shifted by 1 bit.
+	 */
+	bus->dest_addr = slave_addr << 1;
 	if (bus_busy || bus->ber_state) {
 		iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
 		npcm_i2c_reset(bus);
@@ -2163,7 +2175,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	}
 
 	npcm_i2c_init_params(bus);
-	bus->dest_addr = slave_addr;
 	bus->msgs = msgs;
 	bus->msgs_num = num;
 	bus->cmd_err = 0;
-- 
2.34.1

On Fri, Sep 20, 2024 at 06:18:18PM +0800, warp5tw@gmail.com wrote:
> From: Tyrone Ting <kfting@nuvoton.com>
> 
> From: Tyrone Ting <kfting@nuvoton.com>

It seems all your mails have an issue.

> Store the client address earlier since it might get called in
> the i2c_recover_bus logic flow at the early stage of the func()
> npcm_i2c_master_xfer.

You got my comment really wrong.

func() in my example was to refer to _a_ function mentioned in the text.
And IIRC I even posted the example, like: i2c_recover_bus().

-- 
With Best Regards,
Andy Shevchenko

Hi Andy:

Thank you for your feedback.

Andy Shevchenko <andriy.shevchenko@linux.intel.com> 於 2024年9月20日 週五 下午10:33寫道：
>
> On Fri, Sep 20, 2024 at 06:18:18PM +0800, warp5tw@gmail.com wrote:
> > From: Tyrone Ting <kfting@nuvoton.com>
> >
> > From: Tyrone Ting <kfting@nuvoton.com>
>
> It seems all your mails have an issue.
>

Acked in the previous email.

> > Store the client address earlier since it might get called in
> > the i2c_recover_bus logic flow at the early stage of the func()
> > npcm_i2c_master_xfer.
>
> You got my comment really wrong.
>
> func() in my example was to refer to _a_ function mentioned in the text.
> And IIRC I even posted the example, like: i2c_recover_bus().
>

So the commit message in next patch set would be like:
Store the client address earlier since it might get called in
the i2c_recover_bus() logic flow at the early stage of
npcm_i2c_master_xfer().

The code comment would be like:
Previously, the address was stored w/o left-shift by one bit and
with that shift in the following call to npcm_i2c_master_start_xmit().

Since there are cases that the i2c_recover_bus() gets called at the
early stage of npcm_i2c_master_xfer(), the address is
stored with the shift and used in the i2c_recover_bus call().


> --
> With Best Regards,
> Andy Shevchenko
>
>

Have a nice day.

Regards,
Tyrone

On Mon, Sep 23, 2024 at 09:59:31AM +0800, Tyrone Ting wrote:
> Andy Shevchenko <andriy.shevchenko@linux.intel.com> 於 2024年9月20日 週五 下午10:33寫道：
> > On Fri, Sep 20, 2024 at 06:18:18PM +0800, warp5tw@gmail.com wrote:

...

> > > Store the client address earlier since it might get called in
> > > the i2c_recover_bus logic flow at the early stage of the func()
> > > npcm_i2c_master_xfer.
> >
> > You got my comment really wrong.
> >
> > func() in my example was to refer to _a_ function mentioned in the text.
> > And IIRC I even posted the example, like: i2c_recover_bus().
> 
> So the commit message in next patch set would be like:

Yes.

> Store the client address earlier since it might get called in
> the i2c_recover_bus() logic flow at the early stage of
> npcm_i2c_master_xfer().
> 
> The code comment would be like:

Yes!

> Previously, the address was stored w/o left-shift by one bit and
> with that shift in the following call to npcm_i2c_master_start_xmit().
> 
> Since there are cases that the i2c_recover_bus() gets called at the
> early stage of npcm_i2c_master_xfer(), the address is
> stored with the shift and used in the i2c_recover_bus call().

-- 
With Best Regards,
Andy Shevchenko