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| author | Johan Hovold <johan@kernel.org> | 2022-11-29 17:18:19 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-21 19:32:07 +0300 |
| commit | c8bf31a00f4f921259d950f1984fbea518eba557 (patch) | |
| tree | b6eed5b86b7017de2542ee7139a5b98f74df24c2 /drivers | |
| parent | 5b75a004167422f1f4a8af767bd4239e53b3348c (diff) | |
| download | linux-c8bf31a00f4f921259d950f1984fbea518eba557.tar.xz | |
USB: serial: f81534: fix division by zero on line-speed change
commit 188c9c2e0c7f4ae864113f80c40bafb394062271 upstream.
The driver leaves the line speed unchanged in case a requested speed is
not supported. Make sure to handle the case where the current speed is
B0 (hangup) without dividing by zero when determining the clock source.
Fixes: 3aacac02f385 ("USB: serial: f81534: add high baud rate support")
Cc: stable@vger.kernel.org # 4.16
Cc: Ji-Ze Hong (Peter Hong) <hpeter@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/serial/f81534.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/usb/serial/f81534.c b/drivers/usb/serial/f81534.c index 5661fd03e545..e952be683c63 100644 --- a/drivers/usb/serial/f81534.c +++ b/drivers/usb/serial/f81534.c @@ -538,9 +538,6 @@ static int f81534_submit_writer(struct usb_serial_port *port, gfp_t mem_flags) static u32 f81534_calc_baud_divisor(u32 baudrate, u32 clockrate) { - if (!baudrate) - return 0; - /* Round to nearest divisor */ return DIV_ROUND_CLOSEST(clockrate, baudrate); } @@ -570,9 +567,14 @@ static int f81534_set_port_config(struct usb_serial_port *port, u32 baud_list[] = {baudrate, old_baudrate, F81534_DEFAULT_BAUD_RATE}; for (i = 0; i < ARRAY_SIZE(baud_list); ++i) { - idx = f81534_find_clk(baud_list[i]); + baudrate = baud_list[i]; + if (baudrate == 0) { + tty_encode_baud_rate(tty, 0, 0); + return 0; + } + + idx = f81534_find_clk(baudrate); if (idx >= 0) { - baudrate = baud_list[i]; tty_encode_baud_rate(tty, baudrate, baudrate); break; } |