diff mbox series

[1/3] i2c: i2c-cdns: Start read transaction after write to transfer_size reg

Message ID 487c8026791bfd60719403a2df2c54bb0ae99232.1646122610.git.michal.simek@xilinx.com
State Accepted
Commit 1bc2a79a4cde5f703b33342f2fcea8af208614ed
Delegated to: Michal Simek
Headers show
Series i2c: i2c-cdns: Driver fixes | expand

Commit Message

Michal Simek March 1, 2022, 8:16 a.m. UTC 
From: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>

Avoid a race condition where read transaction is started
keeping expected bytes as 0. Which sometimes would result in sending
STOP signal as no data is expected. Observed on QEMU platform.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Reviewed-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

 drivers/i2c/i2c-cdns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-cdns.c b/drivers/i2c/i2c-cdns.c
index a650dd69b89f..5736afb45191 100644
--- a/drivers/i2c/i2c-cdns.c
+++ b/drivers/i2c/i2c-cdns.c
@@ -375,7 +375,6 @@  static int cdns_i2c_read_data(struct i2c_cdns_bus *i2c_bus, u32 addr, u8 *data,
 				curr_recv_count = recv_count;
 			}
 		} else if (recv_count && !hold_quirk && !curr_recv_count) {
-			writel(addr, &regs->address);
 			if (recv_count > CDNS_I2C_TRANSFER_SIZE) {
 				writel(CDNS_I2C_TRANSFER_SIZE,
 				       &regs->transfer_size);
@@ -384,6 +383,7 @@  static int cdns_i2c_read_data(struct i2c_cdns_bus *i2c_bus, u32 addr, u8 *data,
 				writel(recv_count, &regs->transfer_size);
 				curr_recv_count = recv_count;
 			}
+			writel(addr, &regs->address);
 		}
 	}