[PATCH 1/3] i2c: i2c-cdns: Start read transaction after write to transfer_size reg
Michal Simek
michal.simek at xilinx.com
Tue Mar 1 09:16:50 CET 2022
From: Sai Pavan Boddu <sai.pavan.boddu at 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 at xilinx.com>
Reviewed-by: Ashok Reddy Soma <ashok.reddy.soma at xilinx.com>
Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---
drivers/i2c/i2c-cdns.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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, ®s->address);
if (recv_count > CDNS_I2C_TRANSFER_SIZE) {
writel(CDNS_I2C_TRANSFER_SIZE,
®s->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, ®s->transfer_size);
curr_recv_count = recv_count;
}
+ writel(addr, ®s->address);
}
}
--
2.35.1
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