Dear Tyrone,
Thank you for your patch.
Am 21.10.24 um 08:27 schrieb Tyrone Ting:
From: Tyrone Ting <kfting@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Reviewed-by: Tali Perry <tali.perry1@xxxxxxxxx>
---
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
