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

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: <[e-mail]>
Signed-off-by: Frank Li <[e-mail]>
Reviewed-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

drivers/i3c/master/svc-i3c-master.c

···
 #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)
···
 	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);