diff mbox series

[v1,2/7] i2c: npcm: use a software flag to indicate a BER condition

Message ID 20240807100244.16872-3-kfting@nuvoton.com
State New
Headers show
Series i2c: npcm: Bug fixes read/write operation, checkpatch | expand

Commit Message

Tyrone Ting Aug. 7, 2024, 10:02 a.m. UTC 
From: Tyrone Ting <kfting@nuvoton.com>

If not clearing the BB (bus busy) condition in the BER (bus error)
interrupt, the driver causes a timeout and hence the i2c core
doesn't do the i2c transfer retry but returns the driver's return
value to the upper layer instead.

Clear the BB condition in the BER interrupt and a software flag is
used. The driver does an i2c recovery without causing the timeout
if the flag is set.

Fixes: 48acf8292280 ("i2c: Remove redundant comparison in npcm_i2c_reg_slave")
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
---
 drivers/i2c/busses/i2c-npcm7xx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index c8503acdaff8..bd444ff83a8c 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -332,6 +332,7 @@  struct npcm_i2c {
 	u64 nack_cnt;
 	u64 timeout_cnt;
 	u64 tx_complete_cnt;
+	bool ber_state;
 };
 
 static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
@@ -1519,6 +1520,7 @@  static void npcm_i2c_irq_handle_ber(struct npcm_i2c *bus)
 	if (npcm_i2c_is_master(bus)) {
 		npcm_i2c_master_abort(bus);
 	} else {
+		bus->ber_state = true;
 		npcm_i2c_clear_master_status(bus);
 
 		/* Clear BB (BUS BUSY) bit */
@@ -1697,6 +1699,7 @@  static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
 		dev_dbg(bus->dev, "bus%d-0x%x recovery skipped, bus not stuck",
 			bus->num, bus->dest_addr);
 		npcm_i2c_reset(bus);
+		bus->ber_state = false;
 		return 0;
 	}
 
@@ -1761,6 +1764,7 @@  static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
 		if (bus->rec_succ_cnt < ULLONG_MAX)
 			bus->rec_succ_cnt++;
 	}
+	bus->ber_state = false;
 	return status;
 }
 
@@ -2156,7 +2160,7 @@  static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 
 	} while (time_is_after_jiffies(time_left) && bus_busy);
 
-	if (bus_busy) {
+	if (bus_busy || bus->ber_state) {
 		iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
 		npcm_i2c_reset(bus);
 		i2c_recover_bus(adap);