From 995c0ec9a81f9e4e75f280f095534f4ed1a9ea9d Mon Sep 17 00:00:00 2001 From: Jeffery Yu Date: Tue, 16 May 2017 17:46:48 +0200 Subject: [PATCH] platform/chrome: cros_ec_lightbar - Avoid I2C xfer to EC during suspend A Mutex lock in cros_ec_cmd_xfer which may be held by frozen Userspace thread during system suspending. So should not call this routine in suspend thread. Signed-off-by: Jeffery Yu Signed-off-by: Guenter Roeck Signed-off-by: Enric Balletbo i Serra Signed-off-by: Benson Leung --- drivers/platform/chrome/cros_ec_dev.c | 12 ++++-------- drivers/platform/chrome/cros_ec_lightbar.c | 13 +++++++++---- 2 files changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c index 7c26223..b9bf086 100644 --- a/drivers/platform/chrome/cros_ec_dev.c +++ b/drivers/platform/chrome/cros_ec_dev.c @@ -437,8 +437,7 @@ static int ec_device_probe(struct platform_device *pdev) cros_ec_sensors_register(ec); /* Take control of the lightbar from the EC. */ - if (ec_has_lightbar(ec)) - lb_manual_suspend_ctrl(ec, 1); + lb_manual_suspend_ctrl(ec, 1); return 0; @@ -452,8 +451,7 @@ static int ec_device_remove(struct platform_device *pdev) struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); /* Let the EC take over the lightbar again. */ - if (ec_has_lightbar(ec)) - lb_manual_suspend_ctrl(ec, 0); + lb_manual_suspend_ctrl(ec, 0); cros_ec_debugfs_remove(ec); @@ -472,8 +470,7 @@ static int ec_device_suspend(struct device *dev) { struct cros_ec_dev *ec = dev_get_drvdata(dev); - if (ec_has_lightbar(ec)) - lb_suspend(ec); + lb_suspend(ec); return 0; } @@ -482,8 +479,7 @@ static int ec_device_resume(struct device *dev) { struct cros_ec_dev *ec = dev_get_drvdata(dev); - if (ec_has_lightbar(ec)) - lb_resume(ec); + lb_resume(ec); return 0; } diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c index e570c1e..fd2b047 100644 --- a/drivers/platform/chrome/cros_ec_lightbar.c +++ b/drivers/platform/chrome/cros_ec_lightbar.c @@ -43,6 +43,7 @@ static unsigned long lb_interval_jiffies = 50 * HZ / 1000; * If this is true, we won't do anything during suspend/resume. */ static bool userspace_control; +static struct cros_ec_dev *ec_with_lightbar; static ssize_t interval_msec_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -384,6 +385,9 @@ int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable) struct cros_ec_command *msg; int ret; + if (ec != ec_with_lightbar) + return 0; + msg = alloc_lightbar_cmd_msg(ec); if (!msg) return -ENOMEM; @@ -413,7 +417,7 @@ error: int lb_suspend(struct cros_ec_dev *ec) { - if (userspace_control) + if (userspace_control || ec != ec_with_lightbar) return 0; return lb_send_empty_cmd(ec, LIGHTBAR_CMD_SUSPEND); @@ -421,7 +425,7 @@ int lb_suspend(struct cros_ec_dev *ec) int lb_resume(struct cros_ec_dev *ec) { - if (userspace_control) + if (userspace_control || ec != ec_with_lightbar) return 0; return lb_send_empty_cmd(ec, LIGHTBAR_CMD_RESUME); @@ -606,9 +610,10 @@ static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj, return 0; /* Only instantiate this stuff if the EC has a lightbar */ - if (ec_has_lightbar(ec)) + if (ec_has_lightbar(ec)) { + ec_with_lightbar = ec; return a->mode; - + } return 0; } -- 2.7.4