[PATCH] 8250_pci.c: Only check for communication class in serial_pci_guess_board

[PATCH] 8250_pci.c: Only check for communication class in serial_pci_guess_board

[Guan Yung Tseng]

Some multiport serial cards, such as the NI PXI-8430/2, NI PXI-8430/8,
and NI PXI-8432/4 use PCI_CLASS_COMMUNICATION_OTHER and this fail the
serial_pci_is_class_communication test added in the commit 7d8905d06405
("serial: 8250_pci: Enable device after we check black list").

Since these devices are correctly listed in serial_pci_tbl, we
shouldn't need to check the PCI class IDs. This change relocates the
class checking solely into "serial_pci_guess_board" where it had been
before so that the class-check doesn't hinder initialization.

Signed-off-by: Guan Yung Tseng <guan.yung.tseng@ni.com>
---
 drivers/tty/serial/8250/8250_pci.c | 28 +++++++++-------------------
 1 file changed, 9 insertions(+), 19 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 4986b4a..e33a869 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -3382,21 +3382,6 @@ static const struct pci_device_id blacklist[] = {
 	{ PCI_VDEVICE(COMMTECH, PCI_ANY_ID), },
 };
 
-static int serial_pci_is_class_communication(struct pci_dev *dev)
-{
-	/*
-	 * If it is not a communications device or the programming
-	 * interface is greater than 6, give up.
-	 */
-	if ((((dev->class >> 8) != PCI_CLASS_COMMUNICATION_SERIAL) &&
-	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MULTISERIAL) &&
-	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MODEM)) ||
-	    (dev->class & 0xff) > 6)
-		return -ENODEV;
-
-	return 0;
-}
-
 static int serial_pci_is_blacklisted(struct pci_dev *dev)
 {
 	const struct pci_device_id *bldev;
@@ -3427,6 +3412,15 @@ serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
 	int num_iomem, num_port, first_port = -1, i;
 
 	/*
+	 * If it is not a communications device or the programming
+	 * interface is greater than 6, give up.
+	 *
+	 */
+	if ((((dev->class >> 8) != PCI_CLASS_COMMUNICATION_SERIAL) &&
+	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MODEM)) ||
+	    (dev->class & 0xff) > 6)
+		return -ENODEV;
+	/*
 	 * Should we try to make guesses for multiport serial devices later?
 	 */
 	if ((dev->class >> 8) == PCI_CLASS_COMMUNICATION_MULTISERIAL)
@@ -3652,10 +3646,6 @@ pciserial_init_one(struct pci_dev *dev, const struct pci_device_id *ent)
 
 	board = &pci_boards[ent->driver_data];
 
-	rc = serial_pci_is_class_communication(dev);
-	if (rc)
-		return rc;
-
 	rc = serial_pci_is_blacklisted(dev);
 	if (rc)
 		return rc;
-- 
2.7.4

Re: [PATCH] 8250_pci.c: Only check for communication class in serial_pci_guess_board

[Greg KH]

On Thu, Jan 10, 2019 at 04:12:12PM +0800, Guan Yung Tseng wrote:
> Some multiport serial cards, such as the NI PXI-8430/2, NI PXI-8430/8,
> and NI PXI-8432/4 use PCI_CLASS_COMMUNICATION_OTHER and this fail the
> serial_pci_is_class_communication test added in the commit 7d8905d06405
> ("serial: 8250_pci: Enable device after we check black list").
> 
> Since these devices are correctly listed in serial_pci_tbl, we
> shouldn't need to check the PCI class IDs. This change relocates the
> class checking solely into "serial_pci_guess_board" where it had been
> before so that the class-check doesn't hinder initialization.
> 
> Signed-off-by: Guan Yung Tseng <guan.yung.tseng@ni.com>
> ---
>  drivers/tty/serial/8250/8250_pci.c | 28 +++++++++-------------------
>  1 file changed, 9 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
> index 4986b4a..e33a869 100644
> --- a/drivers/tty/serial/8250/8250_pci.c
> +++ b/drivers/tty/serial/8250/8250_pci.c
> @@ -3382,21 +3382,6 @@ static const struct pci_device_id blacklist[] = {
>  	{ PCI_VDEVICE(COMMTECH, PCI_ANY_ID), },
>  };
>  
> -static int serial_pci_is_class_communication(struct pci_dev *dev)
> -{
> -	/*
> -	 * If it is not a communications device or the programming
> -	 * interface is greater than 6, give up.
> -	 */
> -	if ((((dev->class >> 8) != PCI_CLASS_COMMUNICATION_SERIAL) &&
> -	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MULTISERIAL) &&
> -	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MODEM)) ||
> -	    (dev->class & 0xff) > 6)
> -		return -ENODEV;
> -
> -	return 0;
> -}

Please leave this as a function, no need to move it inside another
function at this point in time.

>  static int serial_pci_is_blacklisted(struct pci_dev *dev)
>  {
>  	const struct pci_device_id *bldev;
> @@ -3427,6 +3412,15 @@ serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
>  	int num_iomem, num_port, first_port = -1, i;
>  
>  	/*
> +	 * If it is not a communications device or the programming
> +	 * interface is greater than 6, give up.
> +	 *
> +	 */
> +	if ((((dev->class >> 8) != PCI_CLASS_COMMUNICATION_SERIAL) &&
> +	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MODEM)) ||
> +	    (dev->class & 0xff) > 6)
> +		return -ENODEV;
> +	/*

what happened to the multiserial check?

You should just call the function here.

thanks,

greg k-h