Commit 4850f26a authored by Daniel M German's avatar Daniel M German Committed by Greg Kroah-Hartman
Browse files

usb: clean up some of the computations in adu_read 



Replace ?: with min to calculate the number of bytes in the secondary buffer,
including changing the data type of data_in_secondary to size_t to be
type-consistent. data_in_secondary can never be negative.

Remove some spurious calculations (copy_to_user returns zero on success),
making one variable redundant (i)

This change does not alter the functionality of the code.

Signed-off-by: default avatarDaniel M German <dmg@turingmachine.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 235e6e0a

drivers/usb/misc/adutux.c

+7 −9
Original line number Diff line number Diff line
@@ -343,7 +343,6 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, 
	struct adu_device *dev;

	size_t bytes_read = 0;

	size_t bytes_to_read = count;

	int i;

	int retval = 0;

	int timeout = 0;

	int should_submit = 0;
@@ -371,23 +370,22 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, 
	timeout = COMMAND_TIMEOUT;

	dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);

	while (bytes_to_read) {

		int data_in_secondary = dev->secondary_tail - dev->secondary_head;

		size_t data_in_secondary = dev->secondary_tail - dev->secondary_head;

		dev_dbg(&dev->udev->dev,

			"%s : while, data_in_secondary=%d, status=%d\n",

			"%s : while, data_in_secondary=%zu, status=%d\n",

			__func__, data_in_secondary,

			dev->interrupt_in_urb->status);



		if (data_in_secondary) {

			/* drain secondary buffer */

			int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;

			i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);

			if (i) {

			size_t amount = min(bytes_to_read, data_in_secondary);

			if (copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount)) {

				retval = -EFAULT;

				goto exit;

			}

			dev->secondary_head += (amount - i);

			bytes_read += (amount - i);

			bytes_to_read -= (amount - i);

			dev->secondary_head += amount;

			bytes_read += amount;

			bytes_to_read -= amount;

		} else {

			/* we check the primary buffer */

			spin_lock_irqsave (&dev->buflock, flags);

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