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Message-Id: <20241021062732.5592-3-kfting@nuvoton.com>
Date: Mon, 21 Oct 2024 14:27:30 +0800
From: Tyrone Ting <warp5tw@...il.com>
To: avifishman70@...il.com,
tmaimon77@...il.com,
tali.perry1@...il.com,
venture@...gle.com,
yuenn@...gle.com,
benjaminfair@...gle.com,
andi.shyti@...nel.org,
andriy.shevchenko@...ux.intel.com,
wsa@...nel.org,
rand.sec96@...il.com,
wsa+renesas@...g-engineering.com,
warp5tw@...il.com,
tali.perry@...oton.com,
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KWLIU@...oton.com,
JJLIU0@...oton.com,
kfting@...oton.com
Cc: openbmc@...ts.ozlabs.org,
linux-i2c@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v7 2/4] i2c: npcm: Modify the client address assignment
From: Tyrone Ting <kfting@...oton.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@...oton.com>
Reviewed-by: Tali Perry <tali.perry1@...il.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;
--
2.34.1
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