[PATCH] virtio_console: Use virtio device index to generate port name

[PATCH] virtio_console: Use virtio device index to generate port name

[sjur.brandeland]

From: Sjur Brændeland <sjur.brandeland@stericsson.com>

Use virtio device index for creating unique device port names.
Current index allocation in virtio is based on a monotonically
increasing variable "index". A better handling of this is to
use device index which is allocated by ida.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
---
 drivers/char/virtio_console.c |   16 +++-------------
 1 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index c17b053..031be0b 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -61,9 +61,6 @@ struct ports_driver_data {
 	/* List of all the devices we're handling */
 	struct list_head portdevs;
 
-	/* Number of devices this driver is handling */
-	unsigned int index;
-
 	/*
 	 * This is used to keep track of the number of hvc consoles
 	 * spawned by this driver.  This number is given as the first
@@ -169,9 +166,6 @@ struct ports_device {
 	/* Array of per-port IO virtqueues */
 	struct virtqueue **in_vqs, **out_vqs;
 
-	/* Used for numbering devices for sysfs and debugfs */
-	unsigned int drv_index;
-
 	/* Major number for this device.  Ports will be created as minors. */
 	int chr_major;
 };
@@ -1415,7 +1409,7 @@ static int add_port(struct ports_device *portdev, u32 id)
 	}
 	port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
 				  devt, port, "vport%up%u",
-				  port->portdev->drv_index, id);
+				  port->portdev->vdev->index, id);
 	if (IS_ERR(port->dev)) {
 		err = PTR_ERR(port->dev);
 		dev_err(&port->portdev->vdev->dev,
@@ -1470,7 +1464,7 @@ static int add_port(struct ports_device *portdev, u32 id)
 		 * inspect a port's state at any time
 		 */
 		sprintf(debugfs_name, "vport%up%u",
-			port->portdev->drv_index, id);
+			port->portdev->vdev->index, id);
 		port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
 							 pdrvdata.debugfs_dir,
 							 port,
@@ -1961,16 +1955,12 @@ static int virtcons_probe(struct virtio_device *vdev)
 	portdev->vdev = vdev;
 	vdev->priv = portdev;
 
-	spin_lock_irq(&pdrvdata_lock);
-	portdev->drv_index = pdrvdata.index++;
-	spin_unlock_irq(&pdrvdata_lock);
-
 	portdev->chr_major = register_chrdev(0, "virtio-portsdev",
 					     &portdev_fops);
 	if (portdev->chr_major < 0) {
 		dev_err(&vdev->dev,
 			"Error %d registering chrdev for device %u\n",
-			portdev->chr_major, portdev->drv_index);
+			portdev->chr_major, vdev->index);
 		err = portdev->chr_major;
 		goto free;
 	}
-- 
1.7.5.4

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Re: [PATCH] virtio_console: Use virtio device index to generate port name

[Rusty Russell]

sjur.brandeland@stericsson.com writes:
> From: Sjur Brændeland <sjur.brandeland@stericsson.com>
>
> Use virtio device index for creating unique device port names.
> Current index allocation in virtio is based on a monotonically
> increasing variable "index". A better handling of this is to
> use device index which is allocated by ida.
>
> Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>

This seems to make sense, but I'd need Amit's Ack to verify that the
current numbering isn't important for anyone.

Thanks,
Rusty.

> ---
>  drivers/char/virtio_console.c |   16 +++-------------
>  1 files changed, 3 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index c17b053..031be0b 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -61,9 +61,6 @@ struct ports_driver_data {
>  	/* List of all the devices we're handling */
>  	struct list_head portdevs;
>  
> -	/* Number of devices this driver is handling */
> -	unsigned int index;
> -
>  	/*
>  	 * This is used to keep track of the number of hvc consoles
>  	 * spawned by this driver.  This number is given as the first
> @@ -169,9 +166,6 @@ struct ports_device {
>  	/* Array of per-port IO virtqueues */
>  	struct virtqueue **in_vqs, **out_vqs;
>  
> -	/* Used for numbering devices for sysfs and debugfs */
> -	unsigned int drv_index;
> -
>  	/* Major number for this device.  Ports will be created as minors. */
>  	int chr_major;
>  };
> @@ -1415,7 +1409,7 @@ static int add_port(struct ports_device *portdev, u32 id)
>  	}
>  	port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
>  				  devt, port, "vport%up%u",
> -				  port->portdev->drv_index, id);
> +				  port->portdev->vdev->index, id);
>  	if (IS_ERR(port->dev)) {
>  		err = PTR_ERR(port->dev);
>  		dev_err(&port->portdev->vdev->dev,
> @@ -1470,7 +1464,7 @@ static int add_port(struct ports_device *portdev, u32 id)
>  		 * inspect a port's state at any time
>  		 */
>  		sprintf(debugfs_name, "vport%up%u",
> -			port->portdev->drv_index, id);
> +			port->portdev->vdev->index, id);
>  		port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
>  							 pdrvdata.debugfs_dir,
>  							 port,
> @@ -1961,16 +1955,12 @@ static int virtcons_probe(struct virtio_device *vdev)
>  	portdev->vdev = vdev;
>  	vdev->priv = portdev;
>  
> -	spin_lock_irq(&pdrvdata_lock);
> -	portdev->drv_index = pdrvdata.index++;
> -	spin_unlock_irq(&pdrvdata_lock);
> -
>  	portdev->chr_major = register_chrdev(0, "virtio-portsdev",
>  					     &portdev_fops);
>  	if (portdev->chr_major < 0) {
>  		dev_err(&vdev->dev,
>  			"Error %d registering chrdev for device %u\n",
> -			portdev->chr_major, portdev->drv_index);
> +			portdev->chr_major, vdev->index);
>  		err = portdev->chr_major;
>  		goto free;
>  	}
> -- 
> 1.7.5.4
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Re: [PATCH] virtio_console: Use virtio device index to generate port name

[Amit Shah]

On (Thu) 17 Jan 2013 [13:23:17], sjur.brandeland@stericsson.com wrote:
> From: Sjur Brændeland <sjur.brandeland@stericsson.com>
> 
> Use virtio device index for creating unique device port names.
> Current index allocation in virtio is based on a monotonically
> increasing variable "index". A better handling of this is to
> use device index which is allocated by ida.

This should be fine.  I'm wondering, though, if there's something else
you need from the naming scheme (esp. considering the next patch)?

		Amit

Re: [PATCH] virtio_console: Use virtio device index to generate port name

[Sjur Brændeland]

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On Fri, Jan 25, 2013 at 10:20 AM, Amit Shah <amit.shah@redhat.com> wrote:

> On (Thu) 17 Jan 2013 [13:23:17], sjur.brandeland@stericsson.com wrote:
> > From: Sjur Brændeland <sjur.brandeland@stericsson.com>
> >
> > Use virtio device index for creating unique device port names.
> > Current index allocation in virtio is based on a monotonically
> > increasing variable "index". A better handling of this is to
> > use device index which is allocated by ida.
>
> This should be fine.  I'm wondering, though, if there's something else
> you need from the naming scheme (esp. considering the next patch)?
>

This current patch solves the most critical issue - that the device name
changes for every modem reboot. This is a show-stopper for me. So it would
be
great if this patch could go upstream. The other problem that device name
is non-deterministic is currently only a theoretical problem as we have
only one
remoteproc device.

Regards,
Sjur

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Re: [PATCH] virtio_console: Use virtio device index to generate port name

[Amit Shah]

On (Mon) 11 Feb 2013 [14:12:52], Sjur Brændeland wrote:
> On Fri, Jan 25, 2013 at 10:20 AM, Amit Shah <amit.shah@redhat.com> wrote:
> 
> > On (Thu) 17 Jan 2013 [13:23:17], sjur.brandeland@stericsson.com wrote:
> > > From: Sjur Brændeland <sjur.brandeland@stericsson.com>
> > >
> > > Use virtio device index for creating unique device port names.
> > > Current index allocation in virtio is based on a monotonically
> > > increasing variable "index". A better handling of this is to
> > > use device index which is allocated by ida.
> >
> > This should be fine.  I'm wondering, though, if there's something else
> > you need from the naming scheme (esp. considering the next patch)?
> 
> This current patch solves the most critical issue - that the device name
> changes for every modem reboot. This is a show-stopper for me. So it would
> be
> great if this patch could go upstream. The other problem that device name
> is non-deterministic is currently only a theoretical problem as we have
> only one
> remoteproc device.

OK - I've no problem with the patch.

		Amit

Re: [PATCH] virtio_console: Use virtio device index to generate port name

[Amit Shah]

On (Thu) 17 Jan 2013 [13:23:17], sjur.brandeland@stericsson.com wrote:
> From: Sjur Brændeland <sjur.brandeland@stericsson.com>
> 
> Use virtio device index for creating unique device port names.
> Current index allocation in virtio is based on a monotonically
> increasing variable "index". A better handling of this is to
> use device index which is allocated by ida.
> 
> Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>

Acked-by: Amit Shah <amit.shah@redhat.com>

Rusty, please pick this one up.

Thanks,

		Amit

Re: [PATCH] virtio_console: Use virtio device index to generate port name

[Rusty Russell]

Amit Shah <amit.shah@redhat.com> writes:

> On (Thu) 17 Jan 2013 [13:23:17], sjur.brandeland@stericsson.com wrote:
>> From: Sjur Brændeland <sjur.brandeland@stericsson.com>
>> 
>> Use virtio device index for creating unique device port names.
>> Current index allocation in virtio is based on a monotonically
>> increasing variable "index". A better handling of this is to
>> use device index which is allocated by ida.
>> 
>> Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
>
> Acked-by: Amit Shah <amit.shah@redhat.com>
>
> Rusty, please pick this one up.

In my virtio-next queue now...

Thanks,
Rusty.
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