Re: [PATCH 0/5] V2 usb console improvements series

From: Alan Stern
Date: Wed Mar 17 2010 - 10:31:02 EST


On Tue, 16 Mar 2010, Jason Wessel wrote:

> Part of having the console stable requires that usb sysrq handler get
> executed in a tasklet. The hcd device lock is always held while the
> driver call backs are executed. The means you cannot get the sysrq
> printk's out to the usb console device after the in_flight urb queue
> is filled.

Either I don't understand this comment properly or else it is simply
wrong. HCDs do not continue to hold their locks when handing completed
URBs back to drivers. The giveback call occurs with interrupts
disabled, but no locks are held.

Does this mean one of the patches in your series can be simplified?

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/