From d046fd5e058535dbb98812f414aeb061724dc3b0 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 26 Sep 2019 11:12:27 +0200 Subject: [PATCH] USB: usblcd: drop redundant lcd mutex Drop the redundant lcd mutex introduced by commit 925ce689bb31 ("USB: autoconvert trivial BKL users to private mutex") which replaced an earlier BKL use. The lock serialised calls to open() against other open() and a custom ioctl() returning the bcdDevice (sic!), but neither is needed. Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20190926091228.24634-9-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/usblcd.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c index b898650a5570..732eb1f81368 100644 --- a/drivers/usb/misc/usblcd.c +++ b/drivers/usb/misc/usblcd.c @@ -30,7 +30,6 @@ #define IOCTL_GET_DRV_VERSION 2 -static DEFINE_MUTEX(lcd_mutex); static const struct usb_device_id id_table[] = { { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, { }, @@ -81,12 +80,10 @@ static int lcd_open(struct inode *inode, struct file *file) struct usb_interface *interface; int subminor, r; - mutex_lock(&lcd_mutex); subminor = iminor(inode); interface = usb_find_interface(&lcd_driver, subminor); if (!interface) { - mutex_unlock(&lcd_mutex); printk(KERN_ERR "USBLCD: %s - error, can't find device for minor %d\n", __func__, subminor); return -ENODEV; @@ -101,13 +98,11 @@ static int lcd_open(struct inode *inode, struct file *file) r = usb_autopm_get_interface(interface); if (r < 0) { kref_put(&dev->kref, lcd_delete); - mutex_unlock(&lcd_mutex); return r; } /* save our object in the file's private structure */ file->private_data = dev; - mutex_unlock(&lcd_mutex); return 0; } @@ -176,14 +171,12 @@ static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) switch (cmd) { case IOCTL_GET_HARD_VERSION: - mutex_lock(&lcd_mutex); bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); sprintf(buf, "%1d%1d.%1d%1d", (bcdDevice & 0xF000)>>12, (bcdDevice & 0xF00)>>8, (bcdDevice & 0xF0)>>4, (bcdDevice & 0xF)); - mutex_unlock(&lcd_mutex); if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0) return -EFAULT; break; -- 2.45.2