In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data in one chunk, so the size of data to be write/read to/from TXDATAx/RXDATAx must be less than or equal 32 bytes at a time. Tested on rk3288-pinky board, elan receive 158 bytes data. Suggested-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Addy Ke <addy.ke@xxxxxxxxxxxxxx> Acked-by: Max Schwarz <max.schwarz@xxxxxxxxx> --- Changes in v2: - Use cleaner syntax as suggested by Sergei. - Update commit message as suggested by Wolfram. Changes in v3: - fix typo: maste --> master and double spaces after 'len' drivers/i2c/busses/i2c-rk3x.c | 4 ++++ Changes in v4: - remove unlikely() annotations, suggested by Dmitry Torokhov diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index b8b2b89..31de730 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -323,6 +323,10 @@ 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 */ + if (len > 32) + len = 32; + /* read the data from receive buffer */ for (i = 0; i < len; ++i) { if (i % 4 == 0) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html