Re: [PATCH] i2c: rk3x: fix bug that cause transfer fails in master receive mode

From: Sergei Shtylyov
Date: Thu Aug 21 2014 - 14:04:40 EST


Hello.

On 08/21/2014 09:50 PM, Addy Ke wrote:

In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data
in one transaction, so the size of data to be write/read to/from
TXDATAx/RXDATAx must be less than or equal 32 bytes at a time.

Test on pinky board, elan receive 158 bytes data.

Signed-off-by: Addy Ke <addy.ke@xxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-rk3x.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 69e1185..dc0aa64 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -323,6 +323,9 @@ static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd)
/* ack interrupt */
i2c_writel(i2c, REG_INT_MBRF, REG_IPD);

+ /* Can only handle a maximum of 32 bytes at a time */
+ len = (len > 32) ? 32 : len;

Why not min(len, 32)? Or even:

if (len > 32)
len = 32;

WBR, Sergei

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