From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 C10644508E3 for ; Tue, 20 Jan 2026 18:12:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768932734; cv=none; b=K+qhd0sw/b4R5ij0ZPX07Y4vLdoYfatksApAr797eLVmo8NfZxIZtG5c6gwpyKN3vsf175kZixwkw+uOxMf49NU2xCRHkvh1AGKCqg6C7Op8NJH++xuq7jWMxdcSWw9ztZEBdYWo1lVkGVIK6LAUuSG010wuGYiiS9ilqQtP6mk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768932734; c=relaxed/simple; bh=X8q/v3NnmZ56pCzHno6A/G3yliaiRkgR525oiPqJYzM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=E7lzkIwi+J7F7dfR8Xq5KCPCHo3xVPYgIk3oCvL6YFnU2hMpCpk3GgD9xS7V1tab2BXSQqHM631N0GXukH7KHH+7ZoYpImuEh3yCjaMn58WE0tn7PqjAizkagtuCbSUknJNdCi93+Sn0X68jauy47G/PfvJyCQfylv3ZQBJBjY4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=IYnbLx/v; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="IYnbLx/v" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768932733; x=1800468733; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=X8q/v3NnmZ56pCzHno6A/G3yliaiRkgR525oiPqJYzM=; b=IYnbLx/vZ4hjR3A3U+3UiFnsm/7L2Q3OO1QtG40nd3sEoQsc86SVyPlJ UkPaZYUZ1ye/MSA8Hdz8W1JuCfwaDLimno3872mKWc8+FKyjuzN0aUNjl cRiEdmgRx7aVjS9VFpevgUS2y6z/0MLxGx31K21U4BNiPtRYeevGw0AkC DpYrSmlToieibvFdT0pkfGhYnC/I6XwACGPi8rf9Wmn3FTruqb9u/L2b4 Fmv4jYe20nalPvsod9l45j82EoOS5xDBaVd6E0MMbePjvBOKGhlbgVGVq ki9AlWhz2Fvz+BB/QT3DSJtgL/WRUHLqW2oJV3TFkR8H41CNWerBUfkTf w==; X-CSE-ConnectionGUID: 7kgtspwyTe+CUomdSibKDA== X-CSE-MsgGUID: RKRHbyO3RJG4Mv91cJO1SQ== X-IronPort-AV: E=McAfee;i="6800,10657,11677"; a="70055600" X-IronPort-AV: E=Sophos;i="6.21,241,1763452800"; d="scan'208";a="70055600" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jan 2026 10:12:13 -0800 X-CSE-ConnectionGUID: ipA1arpMQ8yEo+J9NkRuCQ== X-CSE-MsgGUID: ap2iRhKDQ2KcTLzR9X45ew== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,241,1763452800"; d="scan'208";a="205997474" Received: from abityuts-desk.ger.corp.intel.com (HELO mnyman-desk.home) ([10.245.244.215]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jan 2026 10:12:11 -0800 From: Mathias Nyman To: Cc: , =?UTF-8?q?=C5=81ukasz=20Bartosik?= , Mathias Nyman Subject: [PATCH 4/4] xhci: dbc: allow setting manufacturer string through sysfs Date: Tue, 20 Jan 2026 20:11:48 +0200 Message-ID: <20260120181148.128712-5-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260120181148.128712-1-mathias.nyman@linux.intel.com> References: <20260120181148.128712-1-mathias.nyman@linux.intel.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Łukasz Bartosik Add dbc_manufacturer sysfs attribute to allow changing the manufacturer description presented by the debug device when a host requests a string descriptor with iManufacturer index. Value can only be changed while debug capability (DbC) is in disabled state to prevent USB device descriptor change while connected to a USB host. The default value is "Linux Foundation". The string length can be from 1 to 126 characters. String is terminated at null or newline, driver does not support empty string. [ mn: Improve commit message and sysfs entry documentation ] Signed-off-by: Łukasz Bartosik Signed-off-by: Mathias Nyman --- .../testing/sysfs-bus-pci-drivers-xhci_hcd | 13 +++++++ drivers/usb/host/xhci-dbgcap.c | 36 +++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci-drivers-xhci_hcd b/Documentation/ABI/testing/sysfs-bus-pci-drivers-xhci_hcd index d153162d6045..d10e6de3adb2 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci-drivers-xhci_hcd +++ b/Documentation/ABI/testing/sysfs-bus-pci-drivers-xhci_hcd @@ -114,3 +114,16 @@ Description: connected to a USB host. The default value is "Linux USB Debug Target". The field length can be from 1 to 126 characters. + +What: /sys/bus/pci/drivers/xhci_hcd/.../dbc_manufacturer +Date: January 2026 +Contact: Łukasz Bartosik +Description: + The dbc_manufacturer attribute allows to change the manufacturer + string descriptor presented by the debug device when a host + requests a string descriptor with iManufacturer index. + Value can only be changed while debug capability (DbC) is in + disabled state to prevent USB device descriptor change while + connected to a USB host. + The default value is "Linux Foundation". + The field length can be from 1 to 126 characters. diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c index cae98576545e..9fd497e0dc7f 100644 --- a/drivers/usb/host/xhci-dbgcap.c +++ b/drivers/usb/host/xhci-dbgcap.c @@ -1210,6 +1210,40 @@ static ssize_t dbc_bcdDevice_store(struct device *dev, return size; } +static ssize_t dbc_manufacturer_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct xhci_hcd *xhci = hcd_to_xhci(dev_get_drvdata(dev)); + struct xhci_dbc *dbc = xhci->dbc; + + return sysfs_emit(buf, "%s\n", dbc->str.manufacturer); +} + +static ssize_t dbc_manufacturer_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct xhci_hcd *xhci = hcd_to_xhci(dev_get_drvdata(dev)); + struct xhci_dbc *dbc = xhci->dbc; + size_t len; + + if (dbc->state != DS_DISABLED) + return -EBUSY; + + len = strcspn(buf, "\n"); + if (!len) + return -EINVAL; + + if (len > USB_MAX_STRING_LEN) + return -E2BIG; + + memcpy(dbc->str.manufacturer, buf, len); + dbc->str.manufacturer[len] = '\0'; + + return size; +} + static ssize_t dbc_product_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -1367,6 +1401,7 @@ static DEVICE_ATTR_RW(dbc_idProduct); static DEVICE_ATTR_RW(dbc_bcdDevice); static DEVICE_ATTR_RW(dbc_serial); static DEVICE_ATTR_RW(dbc_product); +static DEVICE_ATTR_RW(dbc_manufacturer); static DEVICE_ATTR_RW(dbc_bInterfaceProtocol); static DEVICE_ATTR_RW(dbc_poll_interval_ms); @@ -1377,6 +1412,7 @@ static struct attribute *dbc_dev_attrs[] = { &dev_attr_dbc_bcdDevice.attr, &dev_attr_dbc_serial.attr, &dev_attr_dbc_product.attr, + &dev_attr_dbc_manufacturer.attr, &dev_attr_dbc_bInterfaceProtocol.attr, &dev_attr_dbc_poll_interval_ms.attr, NULL -- 2.43.0