[PATCH 5.7 118/204] USB: serial: ftdi_sio: clean up receive processing

Greg Kroah-Hartman
2020-08-20T09:40:22Z

From: Johan Hovold <johan@kernel.org>

[ Upstream commit ce054039ba5e47b75a3be02a00274e52b06a6456 ]

Clean up receive processing by dropping the character pointer and
keeping the length argument unchanged throughout the function.

Also make it more apparent that sysrq processing can consume a
characters by adding an explicit continue.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/serial/ftdi_sio.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 96b9e2768ac5c..33f1cca7eaa61 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2483,7 +2483,6 @@ static int ftdi_process_packet(struct usb_serial_port *port,
struct ftdi_private *priv, unsigned char *buf, int len)
{
unsigned char status;
- unsigned char *ch;
int i;
char flag;

@@ -2526,8 +2525,7 @@ static int ftdi_process_packet(struct usb_serial_port *port,
else
priv->transmit_empty = 0;

- len -= 2;
- if (!len)
+ if (len == 2)
return 0; /* status only */

/*
@@ -2556,19 +2554,20 @@ static int ftdi_process_packet(struct usb_serial_port *port,
}
}

- port->icount.rx += len;
- ch = buf + 2;
+ port->icount.rx += len - 2;

if (port->port.console && port->sysrq) {
- for (i = 0; i < len; i++, ch++) {
- if (!usb_serial_handle_sysrq_char(port, *ch))
- tty_insert_flip_char(&port->port, *ch, flag);
+ for (i = 2; i < len; i++) {
+ if (usb_serial_handle_sysrq_char(port, buf[i]))
+ continue;
+ tty_insert_flip_char(&port->port, buf[i], flag);
}
} else {
- tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
+ tty_insert_flip_string_fixed_flag(&port->port, buf + 2, flag,
+ len - 2);
}

- return len;
+ return len - 2;
}

static void ftdi_process_read_urb(struct urb *urb)
--
2.25.1