Subject: [PATCH] pcnet32: VLB support fixes

From: Bartlomiej Zolnierkiewicz <[email protected]>
Subject: [PATCH] pcnet32: VLB support fixes

VLB support has been broken since at least 2004-2005 period as some
changes introduced back then assumed that ->pci_dev is always valid,
lets try to fix it:

- remove duplicated SET_NETDEV_DEV() call

- call SET_NETDEV_DEV() only for PCI devices

- check for ->pci_dev validity in pcnet32_open()

[ Alternatively we may consider removing VLB support but there would not
be much gain in it since an extra driver code needed for VLB support is
minimal and quite simple. ]

This takes care of the following entry from Dan's list:

drivers/net/pcnet32.c +1889 pcnet32_probe1(298) warning: variable derefenced before check 'pdev'

Reported-by: Dan Carpenter <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Julia Lawall <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
---
PS I still keep the original cc: list from the smatch thread -- please let
me know if you don't want to be spammed.. ;-)

drivers/net/pcnet32.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

Index: b/drivers/net/pcnet32.c
===================================================================
--- a/drivers/net/pcnet32.c
+++ b/drivers/net/pcnet32.c
@@ -1719,7 +1719,9 @@ pcnet32_probe1(unsigned long ioaddr, int
ret = -ENOMEM;
goto err_release_region;
}
- SET_NETDEV_DEV(dev, &pdev->dev);
+
+ if (pdev)
+ SET_NETDEV_DEV(dev, &pdev->dev);

if (pcnet32_debug & NETIF_MSG_PROBE)
printk(KERN_INFO PFX "%s at %#3lx,", chipname, ioaddr);
@@ -1818,7 +1820,6 @@ pcnet32_probe1(unsigned long ioaddr, int

spin_lock_init(&lp->lock);

- SET_NETDEV_DEV(dev, &pdev->dev);
lp->name = chipname;
lp->shared_irq = shared;
lp->tx_ring_size = TX_RING_SIZE; /* default tx ring size */
@@ -2089,6 +2090,7 @@ static void pcnet32_free_ring(struct net
static int pcnet32_open(struct net_device *dev)
{
struct pcnet32_private *lp = netdev_priv(dev);
+ struct pci_dev *pdev = lp->pci_dev;
unsigned long ioaddr = dev->base_addr;
u16 val;
int i;
@@ -2149,9 +2151,9 @@ static int pcnet32_open(struct net_devic
lp->a.write_csr(ioaddr, 124, val);

/* Allied Telesyn AT 2700/2701 FX are 100Mbit only and do not negotiate */
- if (lp->pci_dev->subsystem_vendor == PCI_VENDOR_ID_AT &&
- (lp->pci_dev->subsystem_device == PCI_SUBDEVICE_ID_AT_2700FX ||
- lp->pci_dev->subsystem_device == PCI_SUBDEVICE_ID_AT_2701FX)) {
+ if (pdev && pdev->subsystem_vendor == PCI_VENDOR_ID_AT &&
+ (pdev->subsystem_device == PCI_SUBDEVICE_ID_AT_2700FX ||
+ pdev->subsystem_device == PCI_SUBDEVICE_ID_AT_2701FX)) {
if (lp->options & PCNET32_PORT_ASEL) {
lp->options = PCNET32_PORT_FD | PCNET32_PORT_100;
if (netif_msg_link(lp))


2009-07-30 21:32:26

by Jeff Garzik

[permalink] [raw]
Subject: Re: [PATCH] pcnet32: VLB support fixes

Bartlomiej Zolnierkiewicz wrote:
> From: Bartlomiej Zolnierkiewicz <[email protected]>
> Subject: [PATCH] pcnet32: VLB support fixes
>
> VLB support has been broken since at least 2004-2005 period as some
> changes introduced back then assumed that ->pci_dev is always valid,
> lets try to fix it:
>
> - remove duplicated SET_NETDEV_DEV() call
>
> - call SET_NETDEV_DEV() only for PCI devices
>
> - check for ->pci_dev validity in pcnet32_open()
>
> [ Alternatively we may consider removing VLB support but there would not
> be much gain in it since an extra driver code needed for VLB support is
> minimal and quite simple. ]
>
> This takes care of the following entry from Dan's list:
>
> drivers/net/pcnet32.c +1889 pcnet32_probe1(298) warning: variable derefenced before check 'pdev'
>
> Reported-by: Dan Carpenter <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: Julia Lawall <[email protected]>
> Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
> ---
> PS I still keep the original cc: list from the smatch thread -- please let
> me know if you don't want to be spammed.. ;-)
>
> drivers/net/pcnet32.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)

ACK -- the patch is correct AFAICS -- but would it not be better to have
a struct device for the VLB device?

We have capability to create struct device for isa and eisa, so VLB is
quite doable.

Jeff, who converted old-ISDN ISA+EISA+PCI drivers to
hotplug model, once upon a time


Subject: Re: [PATCH] pcnet32: VLB support fixes

On Thursday 30 July 2009 23:32:19 Jeff Garzik wrote:
> Bartlomiej Zolnierkiewicz wrote:
> > From: Bartlomiej Zolnierkiewicz <[email protected]>
> > Subject: [PATCH] pcnet32: VLB support fixes
> >
> > VLB support has been broken since at least 2004-2005 period as some
> > changes introduced back then assumed that ->pci_dev is always valid,
> > lets try to fix it:
> >
> > - remove duplicated SET_NETDEV_DEV() call
> >
> > - call SET_NETDEV_DEV() only for PCI devices
> >
> > - check for ->pci_dev validity in pcnet32_open()
> >
> > [ Alternatively we may consider removing VLB support but there would not
> > be much gain in it since an extra driver code needed for VLB support is
> > minimal and quite simple. ]
> >
> > This takes care of the following entry from Dan's list:
> >
> > drivers/net/pcnet32.c +1889 pcnet32_probe1(298) warning: variable derefenced before check 'pdev'
> >
> > Reported-by: Dan Carpenter <[email protected]>
> > Cc: [email protected]
> > Cc: [email protected]
> > Cc: Julia Lawall <[email protected]>
> > Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
> > ---
> > PS I still keep the original cc: list from the smatch thread -- please let
> > me know if you don't want to be spammed.. ;-)
> >
> > drivers/net/pcnet32.c | 12 +++++++-----
> > 1 file changed, 7 insertions(+), 5 deletions(-)
>
> ACK -- the patch is correct AFAICS -- but would it not be better to have
> a struct device for the VLB device?

Sure, such addition would be needed for sysfs support on VLB devices..

> We have capability to create struct device for isa and eisa, so VLB is
> quite doable.
>
> Jeff, who converted old-ISDN ISA+EISA+PCI drivers to
> hotplug model, once upon a time

..and it seems that you've the needed experience! :)

2009-07-30 21:58:06

by Jeff Garzik

[permalink] [raw]
Subject: Re: [PATCH] pcnet32: VLB support fixes

Bartlomiej Zolnierkiewicz wrote:
> On Thursday 30 July 2009 23:32:19 Jeff Garzik wrote:
>> Bartlomiej Zolnierkiewicz wrote:
>>> From: Bartlomiej Zolnierkiewicz <[email protected]>
>>> Subject: [PATCH] pcnet32: VLB support fixes
>>>
>>> VLB support has been broken since at least 2004-2005 period as some
>>> changes introduced back then assumed that ->pci_dev is always valid,
>>> lets try to fix it:
>>>
>>> - remove duplicated SET_NETDEV_DEV() call
>>>
>>> - call SET_NETDEV_DEV() only for PCI devices
>>>
>>> - check for ->pci_dev validity in pcnet32_open()
>>>
>>> [ Alternatively we may consider removing VLB support but there would not
>>> be much gain in it since an extra driver code needed for VLB support is
>>> minimal and quite simple. ]
>>>
>>> This takes care of the following entry from Dan's list:
>>>
>>> drivers/net/pcnet32.c +1889 pcnet32_probe1(298) warning: variable derefenced before check 'pdev'
>>>
>>> Reported-by: Dan Carpenter <[email protected]>
>>> Cc: [email protected]
>>> Cc: [email protected]
>>> Cc: Julia Lawall <[email protected]>
>>> Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
>>> ---
>>> PS I still keep the original cc: list from the smatch thread -- please let
>>> me know if you don't want to be spammed.. ;-)
>>>
>>> drivers/net/pcnet32.c | 12 +++++++-----
>>> 1 file changed, 7 insertions(+), 5 deletions(-)
>> ACK -- the patch is correct AFAICS -- but would it not be better to have
>> a struct device for the VLB device?
>
> Sure, such addition would be needed for sysfs support on VLB devices..


>> We have capability to create struct device for isa and eisa, so VLB is
>> quite doable.
>>
>> Jeff, who converted old-ISDN ISA+EISA+PCI drivers to
>> hotplug model, once upon a time
>
> ..and it seems that you've the needed experience! :)

<grin> In my esteemed experience, I point you to the 39-line
include/linux/isa.h as a starting point for grep... :)

Jeff



Subject: Re: [PATCH] pcnet32: VLB support fixes

On Thursday 30 July 2009 23:58:00 Jeff Garzik wrote:
> Bartlomiej Zolnierkiewicz wrote:
> > On Thursday 30 July 2009 23:32:19 Jeff Garzik wrote:
> >> Bartlomiej Zolnierkiewicz wrote:
> >>> From: Bartlomiej Zolnierkiewicz <[email protected]>
> >>> Subject: [PATCH] pcnet32: VLB support fixes
> >>>
> >>> VLB support has been broken since at least 2004-2005 period as some
> >>> changes introduced back then assumed that ->pci_dev is always valid,
> >>> lets try to fix it:
> >>>
> >>> - remove duplicated SET_NETDEV_DEV() call
> >>>
> >>> - call SET_NETDEV_DEV() only for PCI devices
> >>>
> >>> - check for ->pci_dev validity in pcnet32_open()
> >>>
> >>> [ Alternatively we may consider removing VLB support but there would not
> >>> be much gain in it since an extra driver code needed for VLB support is
> >>> minimal and quite simple. ]
> >>>
> >>> This takes care of the following entry from Dan's list:
> >>>
> >>> drivers/net/pcnet32.c +1889 pcnet32_probe1(298) warning: variable derefenced before check 'pdev'
> >>>
> >>> Reported-by: Dan Carpenter <[email protected]>
> >>> Cc: [email protected]
> >>> Cc: [email protected]
> >>> Cc: Julia Lawall <[email protected]>
> >>> Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
> >>> ---
> >>> PS I still keep the original cc: list from the smatch thread -- please let
> >>> me know if you don't want to be spammed.. ;-)
> >>>
> >>> drivers/net/pcnet32.c | 12 +++++++-----
> >>> 1 file changed, 7 insertions(+), 5 deletions(-)
> >> ACK -- the patch is correct AFAICS -- but would it not be better to have
> >> a struct device for the VLB device?
> >
> > Sure, such addition would be needed for sysfs support on VLB devices..
>
>
> >> We have capability to create struct device for isa and eisa, so VLB is
> >> quite doable.
> >>
> >> Jeff, who converted old-ISDN ISA+EISA+PCI drivers to
> >> hotplug model, once upon a time
> >
> > ..and it seems that you've the needed experience! :)
>
> <grin> In my esteemed experience, I point you to the 39-line
> include/linux/isa.h as a starting point for grep... :)

Send patches.

I don't have a time/motivation for enhancing VLB support, not even
mentioning the access to hardware needed to test such changes..

2009-07-31 18:45:44

by Don Fry

[permalink] [raw]
Subject: Re: [PATCH] pcnet32: VLB support fixes

Acked-by: Don Fry <[email protected]>
---
I do not have any VLB hardware to test this, which is why I probably
introduced the error in 2004/5.

-----Original Message-----
From: Bartlomiej Zolnierkiewicz <[email protected]>
To: Don Fry <[email protected]>
Cc: [email protected], [email protected], Dan Carpenter
<[email protected]>, [email protected], [email protected], Julia Lawall
<[email protected]>
Subject: [PATCH] pcnet32: VLB support fixes
Date: Thu, 30 Jul 2009 23:17:52 +0200

From: Bartlomiej Zolnierkiewicz <[email protected]>
Subject: [PATCH] pcnet32: VLB support fixes

VLB support has been broken since at least 2004-2005 period as some
changes introduced back then assumed that ->pci_dev is always valid,
lets try to fix it:

- remove duplicated SET_NETDEV_DEV() call

- call SET_NETDEV_DEV() only for PCI devices

- check for ->pci_dev validity in pcnet32_open()

[ Alternatively we may consider removing VLB support but there would not
be much gain in it since an extra driver code needed for VLB support is
minimal and quite simple. ]

This takes care of the following entry from Dan's list:

drivers/net/pcnet32.c +1889 pcnet32_probe1(298) warning: variable derefenced before check 'pdev'

Reported-by: Dan Carpenter <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Julia Lawall <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
---
PS I still keep the original cc: list from the smatch thread -- please let
me know if you don't want to be spammed.. ;-)

drivers/net/pcnet32.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

Index: b/drivers/net/pcnet32.c
===================================================================
--- a/drivers/net/pcnet32.c
+++ b/drivers/net/pcnet32.c
@@ -1719,7 +1719,9 @@ pcnet32_probe1(unsigned long ioaddr, int
ret = -ENOMEM;
goto err_release_region;
}
- SET_NETDEV_DEV(dev, &pdev->dev);
+
+ if (pdev)
+ SET_NETDEV_DEV(dev, &pdev->dev);

if (pcnet32_debug & NETIF_MSG_PROBE)
printk(KERN_INFO PFX "%s at %#3lx,", chipname, ioaddr);
@@ -1818,7 +1820,6 @@ pcnet32_probe1(unsigned long ioaddr, int

spin_lock_init(&lp->lock);

- SET_NETDEV_DEV(dev, &pdev->dev);
lp->name = chipname;
lp->shared_irq = shared;
lp->tx_ring_size = TX_RING_SIZE; /* default tx ring size */
@@ -2089,6 +2090,7 @@ static void pcnet32_free_ring(struct net
static int pcnet32_open(struct net_device *dev)
{
struct pcnet32_private *lp = netdev_priv(dev);
+ struct pci_dev *pdev = lp->pci_dev;
unsigned long ioaddr = dev->base_addr;
u16 val;
int i;
@@ -2149,9 +2151,9 @@ static int pcnet32_open(struct net_devic
lp->a.write_csr(ioaddr, 124, val);

/* Allied Telesyn AT 2700/2701 FX are 100Mbit only and do not negotiate */
- if (lp->pci_dev->subsystem_vendor == PCI_VENDOR_ID_AT &&
- (lp->pci_dev->subsystem_device == PCI_SUBDEVICE_ID_AT_2700FX ||
- lp->pci_dev->subsystem_device == PCI_SUBDEVICE_ID_AT_2701FX)) {
+ if (pdev && pdev->subsystem_vendor == PCI_VENDOR_ID_AT &&
+ (pdev->subsystem_device == PCI_SUBDEVICE_ID_AT_2700FX ||
+ pdev->subsystem_device == PCI_SUBDEVICE_ID_AT_2701FX)) {
if (lp->options & PCNET32_PORT_ASEL) {
lp->options = PCNET32_PORT_FD | PCNET32_PORT_100;
if (netif_msg_link(lp))