[PATCH 3.16.y-ckt 020/183] tty/serial: at91: fix error handling in atmel_serial_probe()
From: Luis Henriques
Date: Fri Mar 06 2015 - 06:08:31 EST
3.16.7-ckt8 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
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@xxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
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 fcb08e87873e..60d05fc2c1c4 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2576,7 +2576,7 @@ 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;
@@ -2637,6 +2637,8 @@ 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;
}
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