FAILED: patch "[PATCH] can: gs_usb: gs_can_open(): always configure bitrates before" failed to apply to 6.18-stable tree

PATCH New [email protected] 2 participants 2 messages Mar 16

Subsystems (2)

Stable branch CAN network drivers

lore

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lore

[email protected]

author maintainer

2026-03-16 14:28 UTC #0 lore raw

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 2df6162785f31f1bbb598cfc3b08e4efc88f80b6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026031627-challenge-relenting-a5a1@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2df6162785f31f1bbb598cfc3b08e4efc88f80b6 Mon Sep 17 00:00:00 2001
From: Marc Kleine-Budde <[email protected]>
Date: Thu, 19 Feb 2026 13:57:34 +0100
Subject: [PATCH] can: gs_usb: gs_can_open(): always configure bitrates before
starting device

So far the driver populated the struct can_priv::do_set_bittiming() and struct can_priv::fd::do_set_data_bittiming() callbacks.

Before bringing up the interface, user space has to configure the bitrates. With these callbacks the configuration is directly forwarded into the CAN hardware. Then the interface can be brought up.

An ifdown-ifup cycle (without changing the bit rates) doesn't re-configure the bitrates in the CAN hardware. This leads to a problem with the CANable-2.5 [1] firmware, which resets the configured bit rates during ifdown.

To fix the problem remove both bit timing callbacks and always configure the bitrates in the struct net_device_ops::ndo_open() callback.

[1] https://github.com/Elmue/CANable-2.5-firmware-Slcan-and-Candlelight

Cc [email protected]

Fixes d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")

Link https://patch.msgid.link/20260219-gs_usb-always-configure-bitrates-v2-1-671f8ba5b0a5@pengutronix.de open here

Signed-off-by Marc Kleine-Budde <[email protected]>

drivers/net/can/usb/gs_usb.c +16 -6

index 9d27d6f0c0b5..ec9a7cbbbc69 100644
@@ -772,9 +772,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 	}
 }
 
-static int gs_usb_set_bittiming(struct net_device *netdev)
+static int gs_usb_set_bittiming(struct gs_can *dev)
 {
-	struct gs_can *dev = netdev_priv(netdev);
 	struct can_bittiming *bt = &dev->can.bittiming;
 	struct gs_device_bittiming dbt = {
 		.prop_seg = cpu_to_le32(bt->prop_seg),

@@ -791,9 +790,8 @@ static int gs_usb_set_bittiming(struct net_device *netdev)
 				    GFP_KERNEL);
 }
 
-static int gs_usb_set_data_bittiming(struct net_device *netdev)
+static int gs_usb_set_data_bittiming(struct gs_can *dev)
 {
-	struct gs_can *dev = netdev_priv(netdev);
 	struct can_bittiming *bt = &dev->can.fd.data_bittiming;
 	struct gs_device_bittiming dbt = {
 		.prop_seg = cpu_to_le32(bt->prop_seg),

@@ -1057,6 +1055,20 @@ static int gs_can_open(struct net_device *netdev)
 	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
 		flags |= GS_CAN_MODE_HW_TIMESTAMP;
 
+	rc = gs_usb_set_bittiming(dev);
+	if (rc) {
+		netdev_err(netdev, "failed to set bittiming: %pe\n", ERR_PTR(rc));
+		goto out_usb_kill_anchored_urbs;
+	}
+
+	if (ctrlmode & CAN_CTRLMODE_FD) {
+		rc = gs_usb_set_data_bittiming(dev);
+		if (rc) {
+			netdev_err(netdev, "failed to set data bittiming: %pe\n", ERR_PTR(rc));
+			goto out_usb_kill_anchored_urbs;
+		}
+	}
+
 	/* finally start device */
 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
 	dm.flags = cpu_to_le32(flags);

@@ -1370,7 +1382,6 @@ static struct gs_can *gs_make_candev(unsigned int channel,
 	dev->can.state = CAN_STATE_STOPPED;
 	dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
 	dev->can.bittiming_const = &dev->bt_const;
-	dev->can.do_set_bittiming = gs_usb_set_bittiming;
 
 	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;

@@ -1394,7 +1405,6 @@ static struct gs_can *gs_make_candev(unsigned int channel,
 		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
 		 */
 		dev->can.fd.data_bittiming_const = &dev->bt_const;
-		dev->can.fd.do_set_data_bittiming = gs_usb_set_data_bittiming;
 	}
 
 	if (feature & GS_CAN_FEATURE_TERMINATION) {

Sasha Levin

maintainer

2026-03-16 16:21 UTC #1 lore raw

PATCH 1/1 can: gs_usb: gs_can_open(): always configure bitrates before starting device

From: Marc Kleine-Budde <[email protected]>

[ Upstream commit 2df6162785f31f1bbb598cfc3b08e4efc88f80b6 ]