i3c: master: svc: fix random hot join failure since timeout error

commit 9aaeef113c55248ecf3ab941c2e4460aaa8b8b9a upstream.

master side report:
  silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000

BIT 20: TIMEOUT error
  The module has stalled too long in a frame. This happens when:
  - The TX FIFO or RX FIFO is not handled and the bus is stuck in the
middle of a message,
  - No STOP was issued and between messages,
  - IBI manual is used and no decision was made.
  The maximum stall period is 100 μs.

This can be considered as being just a warning as the system IRQ latency
can easily be greater than 100us.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-7-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 2687112..c395e52 100644 (file)
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -93,6 +93,7 @@
 #define SVC_I3C_MINTMASKED   0x098
 #define SVC_I3C_MERRWARN     0x09C
 #define   SVC_I3C_MERRWARN_NACK BIT(2)
+#define   SVC_I3C_MERRWARN_TIMEOUT BIT(20)
 #define SVC_I3C_MDMACTRL     0x0A0
 #define SVC_I3C_MDATACTRL    0x0AC
 #define   SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
@@ -227,6 +228,14 @@ static bool svc_i3c_master_error(struct svc_i3c_master *master)
        if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
                merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
                writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
+
+               /* Ignore timeout error */
+               if (merrwarn & SVC_I3C_MERRWARN_TIMEOUT) {
+                       dev_dbg(master->dev, "Warning condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
+                               mstatus, merrwarn);
+                       return false;
+               }
+
                dev_err(master->dev,
                        "Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
                        mstatus, merrwarn);