From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752599AbdGEVOr (ORCPT ); Wed, 5 Jul 2017 17:14:47 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:36741 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751796AbdGEVOo (ORCPT ); Wed, 5 Jul 2017 17:14:44 -0400 From: Jack Andersen To: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jack Andersen , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Lee Jones Subject: [PATCH v5 3/3] mfd: dln2: Send restart command if HW init fails Date: Wed, 5 Jul 2017 11:12:48 -1000 Message-Id: <1499289168-14392-3-git-send-email-jackoalan@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1499289168-14392-1-git-send-email-jackoalan@gmail.com> References: <1499289168-14392-1-git-send-email-jackoalan@gmail.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There's an issue with reinitializing DLN2 hardware if ADC channel event configurations aren't reset before suspending the driver. A physical reconnect of the device solves the problem, but restarting the machine without a power cycle leaves the device state inconsistent. This patch transmits a restart command in the event of a failed init. To the kernel's perspective, this is the rough equivalent of a disconnect and reconnect, so another probe occurs shortly afterwards. Signed-off-by: Jack Andersen --- drivers/mfd/dln2.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c index a22ab8c..1eb0056 100644 --- a/drivers/mfd/dln2.c +++ b/drivers/mfd/dln2.c @@ -40,6 +40,7 @@ struct dln2_response { #define DLN2_GENERIC_CMD(cmd) DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID) #define CMD_GET_DEVICE_VER DLN2_GENERIC_CMD(0x30) #define CMD_GET_DEVICE_SN DLN2_GENERIC_CMD(0x31) +#define CMD_RESTART DLN2_GENERIC_CMD(0x43) #define DLN2_HW_ID 0x200 #define DLN2_USB_TIMEOUT 200 /* in ms */ @@ -531,6 +532,12 @@ int dln2_transfer(struct platform_device *pdev, u16 cmd, } EXPORT_SYMBOL(dln2_transfer); +static int dln2_restart(struct dln2_dev *dln2) +{ + return _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_RESTART, + NULL, 0, NULL, NULL); +} + static int dln2_check_hw(struct dln2_dev *dln2) { int ret; @@ -782,7 +789,9 @@ static int dln2_probe(struct usb_interface *interface, ret = dln2_hw_init(dln2); if (ret < 0) { - dev_err(dev, "failed to initialize hardware\n"); + dev_err(dev, + "failed to initialize hardware; attempting restart\n"); + dln2_restart(dln2); goto out_stop_rx; } -- 1.9.1