Re: [PATCH] Revert "i2c: rcar_i2c: Set the slave address from rcar_i2c_xfer"

[Heiko Schocher]

Hello Lad,

Am 21.09.2020 um 18:33 schrieb Lad Prabhakar:

This reverts commit 7c8f821e ("i2c: rcar_i2c: Set the
slave address from rcar_i2c_xfer"), as it blindly called
rcar_i2c_set_addr() with read argument always set to 1
during xfer which introduced read errors, whereas
earlier rcar_i2c_read_common() called rcar_i2c_set_addr()
with read set to 1 and rcar_i2c_write_common() called
rcar_i2c_set_addr() with read set 0.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad...@bp.renesas.com>
Reviewed-by: Biju Das <biju.das...@bp.renesas.com>
---
  drivers/i2c/rcar_i2c.c | 14 +++++++++-----
  1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index 4267bbfa5a..75448c8368 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -162,6 +162,10 @@ static int rcar_i2c_read_common(struct udevice *dev, 
struct i2c_msg *msg)
        u32 icmcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE;
        int i, ret = -EREMOTEIO;

+ ret = rcar_i2c_set_addr(dev, msg->addr, 1);

+       if (ret)
+               return ret;
+
        for (i = 0; i < msg->len; i++) {
                if (msg->len - 1 == i)
                        icmcr |= RCAR_I2C_ICMCR_FSB;
@@ -188,6 +192,10 @@ static int rcar_i2c_write_common(struct udevice *dev, 
struct i2c_msg *msg)
        u32 icmcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE;
        int i, ret = -EREMOTEIO;

+ ret = rcar_i2c_set_addr(dev, msg->addr, 0);

+       if (ret)
+               return ret;
+
        for (i = 0; i < msg->len; i++) {
                writel(msg->buf[i], priv->base + RCAR_I2C_ICRXD_ICTXD);
                writel(icmcr, priv->base + RCAR_I2C_ICMCR);
@@ -211,10 +219,6 @@ static int rcar_i2c_xfer(struct udevice *dev, struct 
i2c_msg *msg, int nmsgs)
        int ret;

for (; nmsgs > 0; nmsgs--, msg++) {

-               ret = rcar_i2c_set_addr(dev, msg->addr, 1);

Instead of reverting, can you do:

rcar_i2c_set_addr(dev, msg->addr, msg->flags & I2C_M_RD);

-               if (ret)
-                       return ret;
-
                if (msg->flags & I2C_M_RD)
                        ret = rcar_i2c_read_common(dev, msg);
                else
@@ -224,7 +228,7 @@ static int rcar_i2c_xfer(struct udevice *dev, struct 
i2c_msg *msg, int nmsgs)
                        return ret;
        }

- return 0;

+       return ret;
  }

static int rcar_i2c_probe_chip(struct udevice *dev, uint addr, uint flags)

bye,
Heiko
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