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Message-Id: <20231019222725.3598022-3-Frank.Li@nxp.com>
Date: Thu, 19 Oct 2023 18:27:21 -0400
From: Frank Li <Frank.Li@....com>
To: miquel.raynal@...tlin.com
Cc: Frank.Li@....com, alexandre.belloni@...tlin.com,
conor.culhane@...vaco.com, imx@...ts.linux.dev, joe@...ches.com,
linux-i3c@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v3 2/6] i3c: master: svc: fix wrong data return when IBI happen during start frame
┌─────┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┌─────
SCL: ┘ └─────┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┘
───┐ ┌─────┐ ┌─────┐ ┌───────────┐
SDA: └───────────────────────┘ └─────┘ └─────┘ └─────
xxx╱ ╲╱ ╲╱ ╲╱ ╲╱ ╲
: xxx╲IBI ╱╲ Addr(0x0a) ╱╲ RW ╱╲NACK╱╲ S ╱
If an In-Band Interrupt (IBI) occurs and IBI work thread is not immediately
scheduled, When svc_i3c_master_priv_xfers() initiates the I3C transfer and
attempts to send address 0x7e, the target interprets it as an
IBI handler and returns the target address 0x0a.
However, svc_i3c_master_priv_xfers() does not handle this case and proceeds
with other transfers, resulting in incorrect data being returned.
Add IBIWON check in svc_i3c_master_xfer(). In case this situation occurs,
return a failure to the driver.
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: stable@...r.kernel.org
Reviewed-by: Miquel Raynal <miquel.raynal@...tlin.com>
Signed-off-by: Frank Li <Frank.Li@....com>
---
Notes:
Change from v1 to v2
- update commit message
- fix typo yeild and falure
drivers/i3c/master/svc-i3c-master.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 8cd708c965085..abebef666b2bb 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1010,6 +1010,9 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
u32 reg;
int ret;
+ /* clean SVC_I3C_MINT_IBIWON w1c bits */
+ writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
+
writel(SVC_I3C_MCTRL_REQUEST_START_ADDR |
xfer_type |
SVC_I3C_MCTRL_IBIRESP_NACK |
@@ -1028,6 +1031,23 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
goto emit_stop;
}
+ /*
+ * According to I3C spec ver 1.1.1, 5.1.2.2.3 Consequence of Controller Starting a Frame
+ * with I3C Target Address.
+ *
+ * The I3C Controller normally should start a Frame, the Address may be arbitrated, and so
+ * the Controller shall monitor to see whether an In-Band Interrupt request, a Controller
+ * Role Request (i.e., Secondary Controller requests to become the Active Controller), or
+ * a Hot-Join Request has been made.
+ *
+ * If missed IBIWON check, the wrong data will be return. When IBIWON happen, return failure
+ * and yield the above events handler.
+ */
+ if (SVC_I3C_MSTATUS_IBIWON(reg)) {
+ ret = -ENXIO;
+ goto emit_stop;
+ }
+
if (rnw)
ret = svc_i3c_master_read(master, in, xfer_len);
else
--
2.34.1
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