[PATCH 2/3] i3c: set i3c_xfer.actual_len in controller drivers

From: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
To: linux-i3c@lists.infradead.org
Cc: meaganlloyd@linux.microsoft.com, alexandre.belloni@bootlin.com,
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Subject: [PATCH 2/3] i3c: set i3c_xfer.actual_len in controller drivers
Date: Fri, 11 Sep 2026 14:09:34 -0700	[thread overview]
Message-ID: <20260911210935.1353126-3-meaganlloyd@linux.microsoft.com> (raw)
In-Reply-To: <20260911210935.1353126-1-meaganlloyd@linux.microsoft.com>

Set i3c_xfer.actual_len for reads across the I3C Controller drivers.

actual_len provides a consistent location for device drivers to know the
read response bytes without overriding the len field.

Signed-off-by: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
---
 drivers/i3c/master/adi-i3c-master.c    | 5 ++++-
 drivers/i3c/master/dw-i3c-master.c     | 4 +++-
 drivers/i3c/master/i3c-master-cdns.c   | 5 ++++-
 drivers/i3c/master/mipi-i3c-hci/core.c | 5 ++++-
 drivers/i3c/master/renesas-i3c.c       | 3 +++
 5 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/i3c/master/adi-i3c-master.c b/drivers/i3c/master/adi-i3c-master.c
index b35386260350..d033bfd4ecc2 100644
--- a/drivers/i3c/master/adi-i3c-master.c
+++ b/drivers/i3c/master/adi-i3c-master.c
@@ -412,8 +412,11 @@ static int adi_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
 
 	ret = xfer->ret;
 
-	for (i = 0; i < nxfers; i++)
+	for (i = 0; i < nxfers; i++) {
 		xfers[i].err = adi_i3c_cmd_get_err(&xfer->cmds[i]);
+		if (xfers[i].rnw)
+			xfers[i].actual_len = xfer->cmds[i].rx_len;
+	}
 
 	return ret;
 }
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 4563d8761ba0..54406e31c870 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1028,8 +1028,10 @@ static int dw_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
 	for (i = 0; i < i3c_nxfers; i++) {
 		struct dw_i3c_cmd *cmd = &xfer->cmds[i];
 
-		if (i3c_xfers[i].rnw)
+		if (i3c_xfers[i].rnw) {
 			i3c_xfers[i].len = cmd->rx_len;
+			i3c_xfers[i].actual_len = cmd->rx_len;
+		}
 	}
 
 	ret = xfer->ret;
diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
index 2d98c1ce9b12..331062c10b31 100644
--- a/drivers/i3c/master/i3c-master-cdns.c
+++ b/drivers/i3c/master/i3c-master-cdns.c
@@ -795,8 +795,11 @@ static int cdns_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
 
 	ret = cdns_xfer->ret;
 
-	for (i = 0; i < nxfers; i++)
+	for (i = 0; i < nxfers; i++) {
 		xfers[i].err = cdns_i3c_cmd_get_err(&cdns_xfer->cmds[i]);
+		if (xfers[i].rnw)
+			xfers[i].actual_len = cdns_xfer->cmds[i].rx_len;
+	}
 
 	cdns_i3c_master_free_xfer(cdns_xfer);
 
diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index dadf049bd4b5..29fa68e29484 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -508,8 +508,11 @@ static int i3c_hci_i3c_xfers(struct i3c_dev_desc *dev,
 	if (ret)
 		goto out;
 	for (i = 0; i < nxfers; i++) {
-		if (i3c_xfers[i].rnw)
+		if (i3c_xfers[i].rnw) {
 			i3c_xfers[i].len = RESP_DATA_LENGTH(xfer[i].response);
+			i3c_xfers[i].actual_len = RESP_DATA_LENGTH(xfer[i].response);
+		}
+
 		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
 			ret = -EIO;
 			goto out;
diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
index 28c0927a0179..a3dcb4cd9b0e 100644
--- a/drivers/i3c/master/renesas-i3c.c
+++ b/drivers/i3c/master/renesas-i3c.c
@@ -918,6 +918,9 @@ static int renesas_i3c_i3c_xfers(struct i3c_dev_desc *dev, struct i3c_xfer *i3c_
 		time_left = renesas_i3c_wait_xfer(i3c, xfer);
 		if (!time_left)
 			xfer_failed = true;
+
+		if (i3c_xfers[i].rnw)
+			i3c_xfers[i].actual_len = cmd->rx_count;
 	}
 
 	if (xfer_failed)
-- 
2.49.0

