[PATCH 3.13.y-ckt 024/143] tty/serial: at91: fix error handling in atmel_serial_probe()

Kamal Mostafa kamal at canonical.com
Tue Mar 31 19:46:29 UTC 2015

3.13.11-ckt18 -stable review patch.  If anyone has any objections, please let me know.


From: Cyrille Pitchen <cyrille.pitchen at 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 at atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 drivers/tty/serial/atmel_serial.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 41060fb..52ada70 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2392,7 +2392,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	ret = atmel_init_port(port, pdev);
 	if (ret)
-		goto err;
+		goto err_clear_bit;
 	if (!atmel_use_pdc_rx(&port->uart)) {
 		ret = -ENOMEM;
@@ -2453,6 +2453,8 @@ err_alloc_ring:
 		port->clk = NULL;
+	clear_bit(port->uart.line, atmel_ports_in_use);
 	return ret;

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