From c85e209b799f12d18a90ae6353b997b1bb1274a5 Mon Sep 17 00:00:00 2001
From: Frank Li <Frank.Li@nxp.com>
Date: Mon, 23 Oct 2023 12:16:55 -0400
Subject: [PATCH] i3c: master: svc: fix ibi may not return mandatory data byte
Git-commit: c85e209b799f12d18a90ae6353b997b1bb1274a5
Patch-mainline: v6.7-rc1
References: git-fixes
MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
creates an issue when the I3C clock is slow, and the CPU is running fast
enough that MSTATUS[RXPEND] may not be updated when the code reaches
checking point. As a result, mandatory data can be missed.
Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is
already in FIFO. It also works without mandatory data.
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-4-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/i3c/master/svc-i3c-master.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 2b2b9c948167..7e83a02573b9 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -333,6 +333,7 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
struct i3c_ibi_slot *slot;
unsigned int count;
u32 mdatactrl;
+ int ret, val;
u8 *buf;
slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
@@ -342,6 +343,13 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
slot->len = 0;
buf = slot->data;
+ ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
+ SVC_I3C_MSTATUS_COMPLETE(val), 0, 1000);
+ if (ret) {
+ dev_err(master->dev, "Timeout when polling for COMPLETE\n");
+ return ret;
+ }
+
while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS)) &&
slot->len < SVC_I3C_FIFO_SIZE) {
mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
--
2.35.3