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USB: serial: io_edgeport: drop buffer-callback sanity checks

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The driver write_room and chars_in_buffer callbacks used to incorrectly
return a negative errno in case they were called while or after the port
had been closed. The return value was later changed to zero by commit
d76f2f4462 ("io_edgeport: Fix various bogus returns to the tty
layer") but the bogus sanity checks were left in place as were the
outdated function-header comments.

These callbacks will never be called for an uninitialised port so drop
the unnecessary sanity checks and the outdated comments.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2021-05-19 11:20:03 +02:00
parent dcbc0ae4f8
commit 9a8253a7c2
1 changed files with 1 additions and 26 deletions
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27
drivers/usb/serial/io_edgeport.c
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@ -1351,9 +1351,7 @@ exit_send:
/*****************************************************************************
* edge_write_room
* this function is called by the tty driver when it wants to know how
* many bytes of data we can accept for a specific port. If successful,
* we return the amount of room that we have for this port (the txCredits)
* otherwise we return a negative error number.
* many bytes of data we can accept for a specific port.
*****************************************************************************/
static unsigned int edge_write_room(struct tty_struct *tty)
{
@ -1362,16 +1360,6 @@ static unsigned int edge_write_room(struct tty_struct *tty)
unsigned int room;
unsigned long flags;
if (edge_port == NULL)
return 0;
if (edge_port->closePending)
return 0;
if (!edge_port->open) {
dev_dbg(&port->dev, "%s - port not opened\n", __func__);
return 0;
}
/* total of both buffers is still txCredit */
spin_lock_irqsave(&edge_port->ep_lock, flags);
room = edge_port->txCredits - edge_port->txfifo.count;
@ -1387,9 +1375,6 @@ static unsigned int edge_write_room(struct tty_struct *tty)
* this function is called by the tty driver when it wants to know how
* many bytes of data we currently have outstanding in the port (data that
* has been written, but hasn't made it out the port yet)
* If successful, we return the number of bytes left to be written in the
* system,
* Otherwise we return a negative error number.
*****************************************************************************/
static unsigned int edge_chars_in_buffer(struct tty_struct *tty)
{
@ -1398,16 +1383,6 @@ static unsigned int edge_chars_in_buffer(struct tty_struct *tty)
unsigned int num_chars;
unsigned long flags;
if (edge_port == NULL)
return 0;
if (edge_port->closePending)
return 0;
if (!edge_port->open) {
dev_dbg(&port->dev, "%s - port not opened\n", __func__);
return 0;
}
spin_lock_irqsave(&edge_port->ep_lock, flags);
num_chars = edge_port->maxTxCredits - edge_port->txCredits +
edge_port->txfifo.count;