From patchwork Tue Aug 10 17:31:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 494907 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B35FCC4338F for ; Tue, 10 Aug 2021 18:06:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9586660EFF for ; Tue, 10 Aug 2021 18:06:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238095AbhHJSGa (ORCPT ); Tue, 10 Aug 2021 14:06:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:37210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239112AbhHJSEx (ORCPT ); Tue, 10 Aug 2021 14:04:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9698361244; Tue, 10 Aug 2021 17:48:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628617718; bh=6QtEQO6FOU2PYeSDEe9WRguwYtnQCN8FsNPIhfcXRRE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l3dYukvMcbpbTmrT8EqqpPT/T1menHzsC5yruFWK+b74TKYRXKfa3EBR7vHPEXG5Q mCGl+jKgQHH0erGGNETNR4v7R7FPw1tb7utsCRnkhA5pRQqj0302Qx/E+63OUH4scp XJ3Ttl46JGiyiQQGGqu8476TXN6mx7pHubZBMsCs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Zaidman , "Aaron Jones (FTDI-UK)" , Jiri Kosina , Sasha Levin Subject: [PATCH 5.13 175/175] HID: ft260: fix device removal due to USB disconnect Date: Tue, 10 Aug 2021 19:31:23 +0200 Message-Id: <20210810173006.709488122@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810173000.928681411@linuxfoundation.org> References: <20210810173000.928681411@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Zaidman [ Upstream commit db8d3a21275c807a4047a21bde3b57d49ca55d82 ] This commit fixes a functional regression introduced by the commit 82f09a637dd3 ("HID: ft260: improve error handling of ft260_hid_feature_report_get()") when upon USB disconnect, the FTDI FT260 i2c device is still available within the /dev folder. In my company's product, where the host USB to FT260 USB connection is hard-wired in the PCB, the issue is not reproducible. To reproduce it, I used the VirtualBox Ubuntu 20.04 VM and the UMFT260EV1A development module for the FTDI FT260 chip: Plug the UMFT260EV1A module into a USB port and attach it to VM. The VM shows 2 i2c devices under the /dev: michael@michael-VirtualBox:~$ ls /dev/i2c-* /dev/i2c-0 /dev/i2c-1 The i2c-0 is not related to the FTDI FT260: michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-0/name SMBus PIIX4 adapter at 4100 The i2c-1 is created by hid-ft260.ko: michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-1/name FT260 usb-i2c bridge on hidraw1 Now, detach the FTDI FT260 USB device from VM. We expect the /dev/i2c-1 to disappear, but it's still here: michael@michael-VirtualBox:~$ ls /dev/i2c-* /dev/i2c-0 /dev/i2c-1 And the kernel log shows: [ +0.001202] usb 2-2: USB disconnect, device number 3 [ +0.000109] ft260 0003:0403:6030.0002: failed to retrieve system status [ +0.000316] ft260 0003:0403:6030.0003: failed to retrieve system status It happens because the commit 82f09a637dd3 changed the ft260_get_system_config() return logic. This caused the ft260_is_interface_enabled() to exit with error upon the FT260 device USB disconnect, which in turn, aborted the ft260_remove() before deleting the FT260 i2c device and cleaning its sysfs stuff. This commit restores the FT260 USB removal functionality and improves the ft260_is_interface_enabled() code to handle correctly all chip modes defined by the device interface configuration pins DCNF0 and DCNF1. Signed-off-by: Michael Zaidman Acked-by: Aaron Jones (FTDI-UK) Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/hid-ft260.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index f43a8406cb9a..e73776ae6976 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -742,7 +742,7 @@ static int ft260_is_interface_enabled(struct hid_device *hdev) int ret; ret = ft260_get_system_config(hdev, &cfg); - if (ret) + if (ret < 0) return ret; ft260_dbg("interface: 0x%02x\n", interface); @@ -754,23 +754,16 @@ static int ft260_is_interface_enabled(struct hid_device *hdev) switch (cfg.chip_mode) { case FT260_MODE_ALL: case FT260_MODE_BOTH: - if (interface == 1) { + if (interface == 1) hid_info(hdev, "uart interface is not supported\n"); - return 0; - } - ret = 1; + else + ret = 1; break; case FT260_MODE_UART: - if (interface == 0) { - hid_info(hdev, "uart is unsupported on interface 0\n"); - ret = 0; - } + hid_info(hdev, "uart interface is not supported\n"); break; case FT260_MODE_I2C: - if (interface == 1) { - hid_info(hdev, "i2c is unsupported on interface 1\n"); - ret = 0; - } + ret = 1; break; } return ret; @@ -1004,11 +997,9 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) static void ft260_remove(struct hid_device *hdev) { - int ret; struct ft260_device *dev = hid_get_drvdata(hdev); - ret = ft260_is_interface_enabled(hdev); - if (ret <= 0) + if (!dev) return; sysfs_remove_group(&hdev->dev.kobj, &ft260_attr_group);