Matthew Wilcox wrote: > On Wed, Sep 03, 2008 at 03:57:13PM -0700, Stephen Hemminger wrote: > > Accessing the VPD area can take a long time. There are comments in the > > SysKonnect vendor driver that it can take up to 25ms. The existing vpd > > access code fails consistently on my hardware. > > Wow, that's slow. If you were to try to read all 32k, it'd take more > than three minutes! (I presume it doesn't actually have as much as 32k). > > > Change the access routines to: > > * use a mutex rather than spinning with IRQ's disabled and lock held > > * have a longer timeout > > * call schedule while spinning to provide some responsivness > > I agree with your approach, but have one minor comment: > > > - spin_lock_irq(&vpd->lock); > > + mutex_lock(&vpd->lock); > > This should be: > > + if (mutex_lock_interruptible(&vpd->lock)) > + return -EINTR; [...] This is fine for the sysfs case, but not if this is called during device probe - we don't want signals to modprobe to break device initialisation, do we? Ben. -- Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
