From: Frank Li Date: Tue, 29 Apr 2025 05:42:34 +0000 (-0400) Subject: i3c: master: svc: skip address resend on repeat START X-Git-Tag: v6.16-rc1~87^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=12cbd157344848b1bd726ecadce27532d79b785a;p=thirdparty%2Fkernel%2Flinux.git 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 Reviewed-by: Miquel Raynal Link: https://lore.kernel.org/r/20250429054234.4013929-1-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni --- diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c index 9b23239ad8db1..279268a180e17 100644 --- 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;