i3c: master: svc: skip address resend on repeat START

According to the I3C specification, address arbitration only happens during
the START. Repeated START do not initiate arbitration, and In-Band
Interrupts (IBIs) cannot occur at this stage.

Resending the address upon a NACK in a repeat START is therefore redundant
and unnecessary. Avoid redundant retries, improving efficiency and ensuring
protocol compliance.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20250429054234.4013929-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 9b23239ad8db173b84a19fb3ff3bc9b77416eb21..279268a180e17487b4d27cde4650f035acebc5bb 100644 (file)
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1277,9 +1277,9 @@ static int svc_i3c_master_write(struct svc_i3c_master *master,
 static int svc_i3c_master_xfer(struct svc_i3c_master *master,
                               bool rnw, unsigned int xfer_type, u8 addr,
                               u8 *in, const u8 *out, unsigned int xfer_len,
-                              unsigned int *actual_len, bool continued)
+                              unsigned int *actual_len, bool continued, bool repeat_start)
 {
-       int retry = 2;
+       int retry = repeat_start ? 1 : 2;
        u32 reg;
        int ret;
 
@@ -1464,7 +1464,7 @@ static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
                ret = svc_i3c_master_xfer(master, cmd->rnw, xfer->type,
                                          cmd->addr, cmd->in, cmd->out,
                                          cmd->len, &cmd->actual_len,
-                                         cmd->continued);
+                                         cmd->continued, i > 0);
                /* cmd->xfer is NULL if I2C or CCC transfer */
                if (cmd->xfer)
                        cmd->xfer->actual_len = cmd->actual_len;