[PATCH 1/1] serial: 8250_pnp: Simplify "line" related code

[PATCH 1/1] serial: 8250_pnp: Simplify "line" related code

[Ilpo Järvinen]

8250_pnp sets drvdata to line + 1 if the probe is successful. The users
of drvdata are in remove, suspend and resume callbacks, none of which
will be called if probe failed. The line acquired from drvdata can
never be zero in those functions and the checks for that can be
removed.

Eliminate also +/-1 step because all users of line subtract 1 from the
value.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/tty/serial/8250/8250_pnp.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 8f72a7de1d1d..fc206afaf671 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -434,8 +434,9 @@ static int
 serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
 	struct uart_8250_port uart, *port;
-	int ret, line, flags = dev_id->driver_data;
+	int ret, flags = dev_id->driver_data;
 	unsigned char iotype;
+	long line;
 
 	if (flags & UNKNOWN_DEV) {
 		ret = serial_pnp_guess_board(dev);
@@ -493,7 +494,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	if (uart_console(&port->port))
 		dev->capabilities |= PNP_CONSOLE;
 
-	pnp_set_drvdata(dev, (void *)((long)line + 1));
+	pnp_set_drvdata(dev, (void *)line);
 	return 0;
 }
 
@@ -502,17 +503,14 @@ static void serial_pnp_remove(struct pnp_dev *dev)
 	long line = (long)pnp_get_drvdata(dev);
 
 	dev->capabilities &= ~PNP_CONSOLE;
-	if (line)
-		serial8250_unregister_port(line - 1);
+	serial8250_unregister_port(line);
 }
 
 static int __maybe_unused serial_pnp_suspend(struct device *dev)
 {
 	long line = (long)dev_get_drvdata(dev);
 
-	if (!line)
-		return -ENODEV;
-	serial8250_suspend_port(line - 1);
+	serial8250_suspend_port(line);
 	return 0;
 }
 
@@ -520,9 +518,7 @@ static int __maybe_unused serial_pnp_resume(struct device *dev)
 {
 	long line = (long)dev_get_drvdata(dev);
 
-	if (!line)
-		return -ENODEV;
-	serial8250_resume_port(line - 1);
+	serial8250_resume_port(line);
 	return 0;
 }
 
-- 
2.39.2

Re: [PATCH 1/1] serial: 8250_pnp: Simplify "line" related code

[Andy Shevchenko]

On Tue, Apr 23, 2024 at 04:49:30PM +0300, Ilpo Järvinen wrote:
> 8250_pnp sets drvdata to line + 1 if the probe is successful. The users
> of drvdata are in remove, suspend and resume callbacks, none of which
> will be called if probe failed. The line acquired from drvdata can
> never be zero in those functions and the checks for that can be
> removed.
> 
> Eliminate also +/-1 step because all users of line subtract 1 from the
> value.

Also noticed that, looks like a leftover from the legacy PM callbacks that
might be called without probe being succeeded.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 1/1] serial: 8250_pnp: Simplify "line" related code

[Greg Kroah-Hartman]

On Tue, Apr 23, 2024 at 04:49:30PM +0300, Ilpo Järvinen wrote:
> 8250_pnp sets drvdata to line + 1 if the probe is successful. The users
> of drvdata are in remove, suspend and resume callbacks, none of which
> will be called if probe failed. The line acquired from drvdata can
> never be zero in those functions and the checks for that can be
> removed.
> 
> Eliminate also +/-1 step because all users of line subtract 1 from the
> value.
> 
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> ---
>  drivers/tty/serial/8250/8250_pnp.c | 16 ++++++----------
>  1 file changed, 6 insertions(+), 10 deletions(-)

Doesn't apply to my tty-next branch, can you rebase and resend?

thanks,


greg k-h