i2c: rcar: bail out on zero length transfers (d7653964) · Commits · 戴 / test

This hardware does not support zero length transfers. Instead, the driver does one (random) byte transfers currently with undefined results for the slaves. We now bail out. Signed-off-by:

Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by:

Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org

drivers/i2c/busses/i2c-rcar.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -561,6 +561,12 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,

		ret = -EINVAL;
		for (i = 0; i < num; i++) {
		/* This HW can't send STOP after address phase */
		if (msgs[i].len == 0) {
		ret = -EOPNOTSUPP;
		break;
		}

		/-------------- spin lock -----------------/
		spin_lock_irqsave(&priv->lock, flags);

		@@ -625,7 +631,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,

		static u32 rcar_i2c_func(struct i2c_adapter *adap)
		{
		return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
		/* This HW can't do SMBUS_QUICK and NOSTART */
		return I2C_FUNC_I2C \| (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
		}

		static const struct i2c_algorithm rcar_i2c_algo = {

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