4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johan Hovold <johan@xxxxxxxxxx>
commit 7a7b5df84b6b4e5d599c7289526eed96541a0654 upstream.
A recent commit fixing DMA-buffers on stack added a shared transfer
buffer protected by a spinlock. This is broken as the USB HID request
callbacks can sleep. Fix this up by replacing the spinlock with a mutex.
Fixes: 1ffb3c40ffb5 ("HID: cp2112: make transfer buffers DMA capable")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hid/hid-cp2112.c | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -167,7 +167,7 @@ struct cp2112_device {
atomic_t xfer_avail;
struct gpio_chip gc;
u8 *in_out_buffer;
- spinlock_t lock;
+ struct mutex lock;
};
static int gpio_push_pull = 0xFF;
@@ -179,10 +179,9 @@ static int cp2112_gpio_direction_input(s
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
- unsigned long flags;
int ret;
- spin_lock_irqsave(&dev->lock, flags);
+ mutex_lock(&dev->lock);
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
@@ -206,7 +205,7 @@ static int cp2112_gpio_direction_input(s
ret = 0;
exit:
- spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock);
return ret <= 0 ? ret : -EIO;
}
@@ -215,10 +214,9 @@ static void cp2112_gpio_set(struct gpio_
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
- unsigned long flags;
int ret;
- spin_lock_irqsave(&dev->lock, flags);
+ mutex_lock(&dev->lock);
buf[0] = CP2112_GPIO_SET;
buf[1] = value ? 0xff : 0;
@@ -230,7 +228,7 @@ static void cp2112_gpio_set(struct gpio_
if (ret < 0)
hid_err(hdev, "error setting GPIO values: %d\n", ret);
- spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock);
}
static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
@@ -238,10 +236,9 @@ static int cp2112_gpio_get(struct gpio_c
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
- unsigned long flags;
int ret;
- spin_lock_irqsave(&dev->lock, flags);
+ mutex_lock(&dev->lock);
ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
@@ -255,7 +252,7 @@ static int cp2112_gpio_get(struct gpio_c
ret = (buf[1] >> offset) & 1;
exit:
- spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock);
return ret;
}
@@ -266,10 +263,9 @@ static int cp2112_gpio_direction_output(
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
- unsigned long flags;
int ret;
- spin_lock_irqsave(&dev->lock, flags);
+ mutex_lock(&dev->lock);
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
@@ -290,7 +286,7 @@ static int cp2112_gpio_direction_output(
goto fail;
}
- spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock);
/*
* Set gpio value when output direction is already set,
@@ -301,7 +297,7 @@ static int cp2112_gpio_direction_output(
return 0;
fail:
- spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock);
return ret < 0 ? ret : -EIO;
}
@@ -1057,7 +1053,7 @@ static int cp2112_probe(struct hid_devic
if (!dev->in_out_buffer)
return -ENOMEM;
- spin_lock_init(&dev->lock);
+ mutex_init(&dev->lock);
ret = hid_parse(hdev);
if (ret) {
--
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