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path: root/drivers/usb/class/usblp.c
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Diffstat (limited to 'drivers/usb/class/usblp.c')
-rw-r--r--drivers/usb/class/usblp.c96
1 files changed, 71 insertions, 25 deletions
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 084c48c5848f..a7a1d38b6bef 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -34,6 +34,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/minmax.h>
#include <linux/sched/signal.h>
#include <linux/signal.h>
#include <linux/poll.h>
@@ -87,7 +88,7 @@
/* Get two-int array: [0]=vendor ID, [1]=product ID: */
#define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
/* Perform class specific soft reset */
-#define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
+#define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0)
/*
* A DEVICE_ID string may include the printer's serial number.
@@ -274,8 +275,25 @@ static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, i
#define usblp_reset(usblp)\
usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
-#define usblp_hp_channel_change_request(usblp, channel, buffer) \
- usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
+static int usblp_hp_channel_change_request(struct usblp *usblp, int channel, u8 *new_channel)
+{
+ u8 *buf;
+ int ret;
+
+ buf = kzalloc(1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST,
+ USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE,
+ channel, buf, 1);
+ if (ret == 0)
+ *new_channel = buf[0];
+
+ kfree(buf);
+
+ return ret;
+}
/*
* See the description for usblp_select_alts() below for the usage
@@ -349,7 +367,8 @@ static int usblp_check_status(struct usblp *usblp, int err)
int error;
mutex_lock(&usblp->mut);
- if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
+ error = usblp_read_status(usblp, usblp->statusbuf);
+ if (error < 0) {
mutex_unlock(&usblp->mut);
printk_ratelimited(KERN_ERR
"usblp%d: error %d reading printer status\n",
@@ -477,16 +496,24 @@ static int usblp_release(struct inode *inode, struct file *file)
/* No kernel lock - fine */
static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
{
- __poll_t ret;
+ struct usblp *usblp = file->private_data;
+ __poll_t ret = 0;
unsigned long flags;
- struct usblp *usblp = file->private_data;
/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
poll_wait(file, &usblp->rwait, wait);
poll_wait(file, &usblp->wwait, wait);
+
+ mutex_lock(&usblp->mut);
+ if (!usblp->present)
+ ret |= EPOLLHUP;
+ mutex_unlock(&usblp->mut);
+
spin_lock_irqsave(&usblp->lock, flags);
- ret = ((usblp->bidir && usblp->rcomplete) ? EPOLLIN | EPOLLRDNORM : 0) |
- ((usblp->no_paper || usblp->wcomplete) ? EPOLLOUT | EPOLLWRNORM : 0);
+ if (usblp->bidir && usblp->rcomplete)
+ ret |= EPOLLIN | EPOLLRDNORM;
+ if (usblp->no_paper || usblp->wcomplete)
+ ret |= EPOLLOUT | EPOLLWRNORM;
spin_unlock_irqrestore(&usblp->lock, flags);
return ret;
}
@@ -726,14 +753,16 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
rv = -EINTR;
goto raise_biglock;
}
- if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
+ rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK));
+ if (rv < 0)
goto raise_wait;
while (writecount < count) {
/*
* Step 1: Submit next block.
*/
- if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
+ transfer_length = count - writecount;
+ if (transfer_length > USBLP_BUF_SIZE)
transfer_length = USBLP_BUF_SIZE;
rv = -ENOMEM;
@@ -751,7 +780,9 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
spin_lock_irq(&usblp->lock);
usblp->wcomplete = 0;
spin_unlock_irq(&usblp->lock);
- if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
+
+ rv = usb_submit_urb(writeurb, GFP_KERNEL);
+ if (rv < 0) {
usblp->wstatus = 0;
spin_lock_irq(&usblp->lock);
usblp->no_paper = 0;
@@ -827,22 +858,29 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, lo
if (rv < 0)
return rv;
- if ((avail = usblp->rstatus) < 0) {
+ if (!usblp->present) {
+ count = -ENODEV;
+ goto done;
+ }
+
+ avail = usblp->rstatus;
+ if (avail < 0) {
printk(KERN_ERR "usblp%d: error %d reading from printer\n",
- usblp->minor, (int)avail);
+ usblp->minor, (int)avail);
usblp_submit_read(usblp);
count = -EIO;
goto done;
}
- count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
+ count = min_t(ssize_t, len, avail - usblp->readcount);
if (count != 0 &&
copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
count = -EFAULT;
goto done;
}
- if ((usblp->readcount += count) == avail) {
+ usblp->readcount += count;
+ if (usblp->readcount == avail) {
if (usblp_submit_read(usblp) < 0) {
/* We don't want to leak USB return codes into errno. */
if (count == 0)
@@ -943,7 +981,8 @@ static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
break;
}
set_current_state(TASK_INTERRUPTIBLE);
- if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
+ rc = usblp_rtest(usblp, nonblock);
+ if (rc < 0) {
mutex_unlock(&usblp->mut);
break;
}
@@ -1001,7 +1040,8 @@ static int usblp_submit_read(struct usblp *usblp)
usblp->readcount = 0; /* XXX Why here? */
usblp->rcomplete = 0;
spin_unlock_irqrestore(&usblp->lock, flags);
- if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
+ rc = usb_submit_urb(urb, GFP_KERNEL);
+ if (rc < 0) {
dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
spin_lock_irqsave(&usblp->lock, flags);
usblp->rstatus = rc;
@@ -1060,7 +1100,7 @@ static const struct file_operations usblp_fops = {
.llseek = noop_llseek,
};
-static char *usblp_devnode(struct device *dev, umode_t *mode)
+static char *usblp_devnode(const struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
}
@@ -1120,7 +1160,8 @@ static int usblp_probe(struct usb_interface *intf,
/* Malloc device ID string buffer to the largest expected length,
* since we can re-query it on an ioctl and a dynamic string
* could change in length. */
- if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
+ usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL);
+ if (!usblp->device_id_string) {
retval = -ENOMEM;
goto abort;
}
@@ -1130,7 +1171,8 @@ static int usblp_probe(struct usb_interface *intf,
* malloc both regardless of bidirectionality, because the
* alternate setting can be changed later via an ioctl.
*/
- if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
+ usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL);
+ if (!usblp->readbuf) {
retval = -ENOMEM;
goto abort;
}
@@ -1310,11 +1352,15 @@ static int usblp_set_protocol(struct usblp *usblp, int protocol)
alts = usblp->protocol[protocol].alt_setting;
if (alts < 0)
return -EINVAL;
- r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
- if (r < 0) {
- printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
- alts, usblp->ifnum);
- return r;
+
+ /* Don't unnecessarily set the interface if there's a single alt. */
+ if (usblp->intf->num_altsetting > 1) {
+ r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
+ if (r < 0) {
+ printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
+ alts, usblp->ifnum);
+ return r;
+ }
}
usblp->bidir = (usblp->protocol[protocol].epread != NULL);
generated by cgit (git 2.34.1) at 2025-12-25 20:51:07 +0000