[PATCH 3.19 116/175] tty/serial: at91: fix error handling in atmel_serial_probe()

Greg Kroah-Hartman
2015-03-04T06:42:09Z

From: Cyrille Pitchen <cyrille.pitchen@atmel.com>

commit 6fbb9bdf0f3fbe23aeff806489791aa876adaffb upstream.

-EDEFER error wasn't handle properly by atmel_serial_probe().
As an example, when atmel_serial_probe() is called for the first time, we pass
the test_and_set_bit() test to check whether the port has already been
initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly
returned before by clk_get(). Consequently atmel_serial_probe() used to return
this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask.
When atmel_serial_probe() was called for the second time, it used to fail on
the test_and_set_bit() function then returning -EBUSY.

When atmel_serial_probe() fails, this patch make it clear the port bit in the
"atmel_ports_in_use" mask, if needed, before returning the error code.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/tty/serial/atmel_serial.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2565,7 +2565,7 @@ static int atmel_serial_probe(struct pla

ret = atmel_init_port(port, pdev);
if (ret)
- goto err;
+ goto err_clear_bit;

if (!atmel_use_pdc_rx(&port->uart)) {
ret = -ENOMEM;
@@ -2628,6 +2628,8 @@ err_alloc_ring:
clk_put(port->clk);
port->clk = NULL;
}
+err_clear_bit:
+ clear_bit(port->uart.line, atmel_ports_in_use);
err:
return ret;
}