Re: [PATCH] iwlwifi MSI support (rev3)

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Thu, 14 Jun 2007 19:02:54 -0400
Jeff Garzik <jeff@garzik.org> wrote:

> Stephen Hemminger wrote:
> > On Thu, 14 Jun 2007 14:52:42 -0400
> > Jeff Garzik <jeff@garzik.org> wrote:
> > 
> >> Stephen Hemminger wrote:
> >>> The previous patch would crash on remove. pci_disable_msi has to be
> >>> called after free_irq.  FYI - pci_disable_msi is safe if MSI hasn't been
> >>> enabled.
> >>>
> >>> --- a/drivers/net/wireless/mac80211/iwlwifi/base.c	2007-06-13 11:10:10.000000000 -0700
> >>> +++ b/drivers/net/wireless/mac80211/iwlwifi/base.c	2007-06-14 11:47:01.000000000 -0700
> >>> @@ -8117,10 +8117,13 @@ static int iwl_pci_probe(struct pci_dev 
> >>>  	/* If power management is turned on, default to AC mode */
> >>>  	priv->power_mode = IWL_POWER_AC;
> >>>  	priv->user_txpower_limit = IWL_DEFAULT_TX_POWER;
> >>> +
> >>> +	pci_enable_msi(pdev);
> >> The API wants fixing, if code that fails to check return value of 
> >> pci_enable_msi() is being written.
> >>
> >> We should definitely be checking the return value there...
> >>
> >> 	Jeff
> >>
> > 
> > I don't understand. pci_enable_msi() returns error if device doesn't
> > do MSI, that's fine.
> 
> It also returns errors for conditions other than "doesn't do MSI", and 
> therein lies the problem with not checking return values.

Errors:
	Not MSI device  - don't care
	MSI disabled globally	- don-t care
	Already doing MSI-X  - message already, don't care
	Out of memory can't setup - don't care

The error codes are a mess so it is better to just not print anything
and just continue on with normal INT mode.