| Message ID | 20240920101820.44850-5-kfting@nuvoton.com |
|---|---|
| State | New |
| Headers | show |
| Series | i2c: npcm: read/write operation, checkpatch | expand |
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().
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;