From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D479334C1C for ; Mon, 16 Mar 2026 16:21:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773678063; cv=none; b=iUwsEHgPvhF+AUZI0M5xQ/jgKgBz6KywDvlPusWw6e6o971m8Nt5PXEWE7SeNbCDtDz9DMgT/5GrOZexo6AHnAT/J7arPQEyO9Mh9i2OVu978l+jQuq0Xt038yMaI53Nf+fUuvEqwLPFgWbY1zuKSReS67+V2WP0+TJabDbUgDE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773678063; c=relaxed/simple; bh=5Jbkko11dGP+XuoPmXkWCngmJVfSxKJSD1BF/syq0vE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aKqiu++s3R26wtiKAp9sLRbdvQc9Zz+G9KPKZoz1fD5hALZBrbioqyJpbBWXCHfkOu6JHd9LvdctpUuGeIyZWX47e/NwKa0UYtLMjdpWOGKb365Pc3eWwIoC6XQL3oX+BJjs0u9epLF7nU4UxalkK9LoA3+LemB3I+lCE0NQV8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rRT4EFUt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rRT4EFUt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A33AFC19421; Mon, 16 Mar 2026 16:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773678063; bh=5Jbkko11dGP+XuoPmXkWCngmJVfSxKJSD1BF/syq0vE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rRT4EFUtamlgWAG4qe/6N9zvuR1/Pzcwgjqm4RKyAa7zF5ClLC0S8imWBQiOMhTNn k8s5nY6+n68iTRq3GmsFm4jfBjY2YylaZCYaAe92SH2u8yO+sHpA/85t7vOVh0M0an uKlVaQ21NWa9xnUGwSTpUNuwBOxsgaM7/v5tQnC6L0sSeMIGtYpFZqimBkFW9t5xNA 1VYv9l5cwOcd3/Uj1BggTno7+3mjgKFbwvs8W5GQJhA1/36AU1CTgJbJK6+W/ZHP7T aSJlizma+vbmLTNReq1ufl/0QCYsogtz1rpLyCP2vO7JP5viucGElnwZKneThQc3+X gihxihsCgPyfw== From: Sasha Levin To: stable@vger.kernel.org Cc: Marc Kleine-Budde , Sasha Levin Subject: [PATCH 6.18.y] can: gs_usb: gs_can_open(): always configure bitrates before starting device Date: Mon, 16 Mar 2026 12:21:00 -0400 Message-ID: <20260316162100.915732-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2026031627-challenge-relenting-a5a1@gregkh> References: <2026031627-challenge-relenting-a5a1@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Marc Kleine-Budde [ Upstream commit 2df6162785f31f1bbb598cfc3b08e4efc88f80b6 ] 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: stable@vger.kernel.org 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 Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/usb/gs_usb.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index 861b583935225..e336703b941ef 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -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); @@ -1357,7 +1369,6 @@ 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; @@ -1381,7 +1392,6 @@ 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) { -- 2.51.0