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
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 | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index c96a25d37c14..a9a9b21f1f0b 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -2155,6 +2155,16 @@ 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 7-bit address was stored and being converted to
+ * the address of event 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 of event is stored
+ * and then used in the i2c_recover_bus().
+ */
+ bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
+
/*
* Check the BER (bus error) state, when ber_state is true, it means that the module
* detects the bus error which is caused by some factor like that the electricity
@@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
* bus is busy.
*/
if (bus_busy || bus->ber_state) {
+ /*
+ * Since the transfer might be a read operation, remove the I2C_M_RD flag
+ * from the bus->dest_addr for the i2c_recover_bus() call later.
+ *
+ * The i2c_recover_bus() uses the address in a write direction to recover
+ * the i2c bus if some error condition occurs.
+ */
+ bus->dest_addr &= ~I2C_M_RD;
+
iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
npcm_i2c_reset(bus);
i2c_recover_bus(adap);
@@ -2172,7 +2191,6 @@ 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;
--
2.34.1Hi Tyrone,
...
> + /*
> + * Previously, the 7-bit address was stored and being converted to
> + * the address of event in the following call to npcm_i2c_master_start_xmit().
Do we care how it was done previously? I think this is not a
useful information as the code readers will se the code the way
it is now, not the way it was done "previously".
(there is a related comment at the end)
> + * Since there are cases that the i2c_recover_bus() gets called at the
> + * early stage of npcm_i2c_master_xfer(), the address of event is stored
> + * and then used in the i2c_recover_bus().
I could rephrase this sentence to something like:
/*
* Store the address early in a global position to ensure it is
* accessible for a potential call to i2c_recover_bus().
*/
> + */
> + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> +
> /*
> * Check the BER (bus error) state, when ber_state is true, it means that the module
> * detects the bus error which is caused by some factor like that the electricity
> @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> * bus is busy.
> */
> if (bus_busy || bus->ber_state) {
> + /*
> + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> + * from the bus->dest_addr for the i2c_recover_bus() call later.
> + *
> + * The i2c_recover_bus() uses the address in a write direction to recover
> + * the i2c bus if some error condition occurs.
> + */
> + bus->dest_addr &= ~I2C_M_RD;
> +
> iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> npcm_i2c_reset(bus);
> i2c_recover_bus(adap);
> @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> }
>
> npcm_i2c_init_params(bus);
> - bus->dest_addr = slave_addr;
We can now get rid of slave_addr. It's just used in
npcm_i2c_master_start_xmit(). Right?
Andi
> bus->msgs = msgs;
> bus->msgs_num = num;
> bus->cmd_err = 0;
> --
> 2.34.1
>
Hi Andi:
Thank you for your comments.
Andi Shyti <andi.shyti@kernel.org> 於 2024年10月24日 週四 下午6:04寫道：
>
> Hi Tyrone,
>
> ...
>
> > + /*
> > + * Previously, the 7-bit address was stored and being converted to
> > + * the address of event in the following call to npcm_i2c_master_start_xmit().
>
> Do we care how it was done previously? I think this is not a
> useful information as the code readers will se the code the way
> it is now, not the way it was done "previously".
>
Yes, it's not a useful information anymore.
> (there is a related comment at the end)
>
> > + * Since there are cases that the i2c_recover_bus() gets called at the
> > + * early stage of npcm_i2c_master_xfer(), the address of event is stored
> > + * and then used in the i2c_recover_bus().
>
> I could rephrase this sentence to something like:
>
> /*
> * Store the address early in a global position to ensure it is
> * accessible for a potential call to i2c_recover_bus().
> */
Understood. Thank you for your help on this.
>
> > + */
> > + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> > +
> > /*
> > * Check the BER (bus error) state, when ber_state is true, it means that the module
> > * detects the bus error which is caused by some factor like that the electricity
> > @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > * bus is busy.
> > */
> > if (bus_busy || bus->ber_state) {
> > + /*
> > + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> > + * from the bus->dest_addr for the i2c_recover_bus() call later.
> > + *
> > + * The i2c_recover_bus() uses the address in a write direction to recover
> > + * the i2c bus if some error condition occurs.
> > + */
> > + bus->dest_addr &= ~I2C_M_RD;
> > +
> > iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> > npcm_i2c_reset(bus);
> > i2c_recover_bus(adap);
> > @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > }
> >
> > npcm_i2c_init_params(bus);
> > - bus->dest_addr = slave_addr;
>
> We can now get rid of slave_addr. It's just used in
> npcm_i2c_master_start_xmit(). Right?
Yes, slave_addr is just used as the link
https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182
suggests with this patch.
>
> Andi
>
> > bus->msgs = msgs;
> > bus->msgs_num = num;
> > bus->cmd_err = 0;
> > --
> > 2.34.1
> >
Thank you.
Regards,
Tyrone
Hi Tyrone, Sorry for the late reply! ... > > > @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, > > > } > > > > > > npcm_i2c_init_params(bus); > > > - bus->dest_addr = slave_addr; > > > > We can now get rid of slave_addr. It's just used in > > npcm_i2c_master_start_xmit(). Right? > > Yes, slave_addr is just used as the link > https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182 > suggests with this patch. What I mean is that slave_addr now is completely unused. We declare it, we initialize it to msg0->addr and it stays like this. What I'm suggesting is to remove it completely. Andi
Hi Andi: Thank you for your reply. Andi Shyti <andi.shyti@kernel.org> 於 2024年11月20日 週三 上午6:22寫道： > > Hi Tyrone, > > Sorry for the late reply! > > ... > > > > > @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, > > > > } > > > > > > > > npcm_i2c_init_params(bus); > > > > - bus->dest_addr = slave_addr; > > > > > > We can now get rid of slave_addr. It's just used in > > > npcm_i2c_master_start_xmit(). Right? > > > > Yes, slave_addr is just used as the link > > https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182 > > suggests with this patch. > > What I mean is that slave_addr now is completely unused. We > declare it, we initialize it to msg0->addr and it stays like > this. > > What I'm suggesting is to remove it completely. > Sorry that I might not describe it clearly in previous discussion thread. slave_addr is passed to npcm_i2c_master_start_xmit() as https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182 suggests. If slave_addr is removed, may I use "(bus->dest_addr &= ~I2C_M_RD)" to replace the slave_addr parameter to npcm_i2c_master_start_xmit()? > Andi Thank you. Regards, Tyrone
Hi Andi:
Sorry to bother you.
May I have your comments about my feedback on these patches?
It'll be great to know if I need to prepare the next patch set for reviewing.
Tyrone Ting <warp5tw@gmail.com> 於 2024年10月25日 週五 上午9:43寫道：
>
> Hi Andi:
>
> Thank you for your comments.
>
> Andi Shyti <andi.shyti@kernel.org> 於 2024年10月24日 週四 下午6:04寫道：
> >
> > Hi Tyrone,
> >
> > ...
> >
> > > + /*
> > > + * Previously, the 7-bit address was stored and being converted to
> > > + * the address of event in the following call to npcm_i2c_master_start_xmit().
> >
> > Do we care how it was done previously? I think this is not a
> > useful information as the code readers will se the code the way
> > it is now, not the way it was done "previously".
> >
>
> Yes, it's not a useful information anymore.
>
> > (there is a related comment at the end)
> >
> > > + * Since there are cases that the i2c_recover_bus() gets called at the
> > > + * early stage of npcm_i2c_master_xfer(), the address of event is stored
> > > + * and then used in the i2c_recover_bus().
> >
> > I could rephrase this sentence to something like:
> >
> > /*
> > * Store the address early in a global position to ensure it is
> > * accessible for a potential call to i2c_recover_bus().
> > */
>
> Understood. Thank you for your help on this.
>
> >
> > > + */
> > > + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> > > +
> > > /*
> > > * Check the BER (bus error) state, when ber_state is true, it means that the module
> > > * detects the bus error which is caused by some factor like that the electricity
> > > @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > > * bus is busy.
> > > */
> > > if (bus_busy || bus->ber_state) {
> > > + /*
> > > + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> > > + * from the bus->dest_addr for the i2c_recover_bus() call later.
> > > + *
> > > + * The i2c_recover_bus() uses the address in a write direction to recover
> > > + * the i2c bus if some error condition occurs.
> > > + */
> > > + bus->dest_addr &= ~I2C_M_RD;
> > > +
> > > iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> > > npcm_i2c_reset(bus);
> > > i2c_recover_bus(adap);
> > > @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > > }
> > >
> > > npcm_i2c_init_params(bus);
> > > - bus->dest_addr = slave_addr;
> >
> > We can now get rid of slave_addr. It's just used in
> > npcm_i2c_master_start_xmit(). Right?
>
> Yes, slave_addr is just used as the link
> https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182
> suggests with this patch.
>
> >
> > Andi
> >
> > > bus->msgs = msgs;
> > > bus->msgs_num = num;
> > > bus->cmd_err = 0;
> > > --
> > > 2.34.1
> > >
>
> Thank you.
>
> Regards,
> Tyrone
Have a nice day.
Thank you.
Regards,
Tyrone
Hi Andi:
May I have your comments about my feedback on these patches?
Tyrone Ting <warp5tw@gmail.com> 於 2024年10月29日 週二 下午4:50寫道：
>
> Hi Andi:
>
> Sorry to bother you.
>
> May I have your comments about my feedback on these patches?
>
> It'll be great to know if I need to prepare the next patch set for reviewing.
>
> Tyrone Ting <warp5tw@gmail.com> 於 2024年10月25日 週五 上午9:43寫道：
> >
> > Hi Andi:
> >
> > Thank you for your comments.
> >
> > Andi Shyti <andi.shyti@kernel.org> 於 2024年10月24日 週四 下午6:04寫道：
> > >
> > > Hi Tyrone,
> > >
> > > ...
> > >
> > > > + /*
> > > > + * Previously, the 7-bit address was stored and being converted to
> > > > + * the address of event in the following call to npcm_i2c_master_start_xmit().
> > >
> > > Do we care how it was done previously? I think this is not a
> > > useful information as the code readers will se the code the way
> > > it is now, not the way it was done "previously".
> > >
> >
> > Yes, it's not a useful information anymore.
> >
> > > (there is a related comment at the end)
> > >
> > > > + * Since there are cases that the i2c_recover_bus() gets called at the
> > > > + * early stage of npcm_i2c_master_xfer(), the address of event is stored
> > > > + * and then used in the i2c_recover_bus().
> > >
> > > I could rephrase this sentence to something like:
> > >
> > > /*
> > > * Store the address early in a global position to ensure it is
> > > * accessible for a potential call to i2c_recover_bus().
> > > */
> >
> > Understood. Thank you for your help on this.
> >
> > >
> > > > + */
> > > > + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> > > > +
> > > > /*
> > > > * Check the BER (bus error) state, when ber_state is true, it means that the module
> > > > * detects the bus error which is caused by some factor like that the electricity
> > > > @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > > > * bus is busy.
> > > > */
> > > > if (bus_busy || bus->ber_state) {
> > > > + /*
> > > > + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> > > > + * from the bus->dest_addr for the i2c_recover_bus() call later.
> > > > + *
> > > > + * The i2c_recover_bus() uses the address in a write direction to recover
> > > > + * the i2c bus if some error condition occurs.
> > > > + */
> > > > + bus->dest_addr &= ~I2C_M_RD;
> > > > +
> > > > iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> > > > npcm_i2c_reset(bus);
> > > > i2c_recover_bus(adap);
> > > > @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > > > }
> > > >
> > > > npcm_i2c_init_params(bus);
> > > > - bus->dest_addr = slave_addr;
> > >
> > > We can now get rid of slave_addr. It's just used in
> > > npcm_i2c_master_start_xmit(). Right?
> >
> > Yes, slave_addr is just used as the link
> > https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182
> > suggests with this patch.
> >
> > >
> > > Andi
> > >
> > > > bus->msgs = msgs;
> > > > bus->msgs_num = num;
> > > > bus->cmd_err = 0;
> > > > --
> > > > 2.34.1
> > > >
> >
> > Thank you.
> >
> > Regards,
> > Tyrone
>
> Have a nice day.
>
> Thank you.
>
> Regards,
> Tyrone
Thank you.
Regards,
Tyrone
Dear Tyrone,
Thank you for your patch.
Am 21.10.24 um 08:27 schrieb Tyrone Ting:
> 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
> npcm_i2c_master_xfer().
Thank you for the description. For the summary/title it’d be great, if
you were more specific. For example:
i2c: npcm: Assign client address earlier for `i2c_recover_bus()`
It’d be great if you noted the commit, your patch fixes, so it’s clear
since when the problem has been present.
> Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
> Reviewed-by: Tali Perry <tali.perry1@gmail.com>
> ---
> drivers/i2c/busses/i2c-npcm7xx.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> index c96a25d37c14..a9a9b21f1f0b 100644
> --- a/drivers/i2c/busses/i2c-npcm7xx.c
> +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> @@ -2155,6 +2155,16 @@ 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 7-bit address was stored and being converted to
> + * the address of event 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 of event is stored
> + * and then used in the i2c_recover_bus().
> + */
> + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> +
> /*
> * Check the BER (bus error) state, when ber_state is true, it means that the module
> * detects the bus error which is caused by some factor like that the electricity
> @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> * bus is busy.
> */
> if (bus_busy || bus->ber_state) {
> + /*
> + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> + * from the bus->dest_addr for the i2c_recover_bus() call later.
> + *
> + * The i2c_recover_bus() uses the address in a write direction to recover
> + * the i2c bus if some error condition occurs.
> + */
> + bus->dest_addr &= ~I2C_M_RD;
> +
> iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> npcm_i2c_reset(bus);
> i2c_recover_bus(adap);
> @@ -2172,7 +2191,6 @@ 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;
Kind regards,
Paul
Hi Paul:
Thank you for your comment.
It'll be addressed in the next patch set.
Paul Menzel <pmenzel@molgen.mpg.de> 於 2024年10月21日 週一 下午3:01寫道：
>
> Dear Tyrone,
>
>
> Thank you for your patch.
>
> Am 21.10.24 um 08:27 schrieb Tyrone Ting:
> > 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
> > npcm_i2c_master_xfer().
>
> Thank you for the description. For the summary/title it’d be great, if
> you were more specific. For example:
>
> i2c: npcm: Assign client address earlier for `i2c_recover_bus()`
>
> It’d be great if you noted the commit, your patch fixes, so it’s clear
> since when the problem has been present.
>
> > Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
> > Reviewed-by: Tali Perry <tali.perry1@gmail.com>
> > ---
> > drivers/i2c/busses/i2c-npcm7xx.c | 20 +++++++++++++++++++-
> > 1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> > index c96a25d37c14..a9a9b21f1f0b 100644
> > --- a/drivers/i2c/busses/i2c-npcm7xx.c
> > +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> > @@ -2155,6 +2155,16 @@ 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 7-bit address was stored and being converted to
> > + * the address of event 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 of event is stored
> > + * and then used in the i2c_recover_bus().
> > + */
> > + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> > +
> > /*
> > * Check the BER (bus error) state, when ber_state is true, it means that the module
> > * detects the bus error which is caused by some factor like that the electricity
> > @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > * bus is busy.
> > */
> > if (bus_busy || bus->ber_state) {
> > + /*
> > + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> > + * from the bus->dest_addr for the i2c_recover_bus() call later.
> > + *
> > + * The i2c_recover_bus() uses the address in a write direction to recover
> > + * the i2c bus if some error condition occurs.
> > + */
> > + bus->dest_addr &= ~I2C_M_RD;
> > +
> > iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> > npcm_i2c_reset(bus);
> > i2c_recover_bus(adap);
> > @@ -2172,7 +2191,6 @@ 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;
>
>
> Kind regards,
>
> Paul
Have a nice day.
Regards,
Tyrone
Hi Tyrone, On Tue, Oct 22, 2024 at 04:08:46PM +0800, Tyrone Ting wrote: > Hi Paul: > > Thank you for your comment. > > It'll be addressed in the next patch set. No need to resend, I can take care of it. Andi
HI Andi: Thank you for your help on this. Andi Shyti <andi.shyti@kernel.org> 於 2024年10月24日 週四 下午5:28寫道： > > Hi Tyrone, > > On Tue, Oct 22, 2024 at 04:08:46PM +0800, Tyrone Ting wrote: > > Hi Paul: > > > > Thank you for your comment. > > > > It'll be addressed in the next patch set. > > No need to resend, I can take care of it. > > Andi Have a nice day. Regards, Tyrone
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