On Tue, 6 Dec 2005 11:40:41 -0800 Greg KH <[EMAIL PROTECTED]> wrote: | On Tue, Dec 06, 2005 at 09:56:10AM -0200, Luiz Fernando Capitulino wrote: | > Greg, | > | > Don't get scared. :-) | > | > As showed by Eduardo Habkost some days ago, the spin lock 'lock' in the | > struct 'usb_serial_port' is being used by some USB serial drivers to protect | > the access to the 'write_urb_busy' member of the same struct. | > | > The spin lock however, is needless: we can change 'write_urb_busy' type | > to be atomic_t and remove all the spin lock usage. | | But if you do that, you make things slower on non-smp machines, which | isn't very nice. Why does the spinlock bother you?
The spinlock makes the code less clear, error prone, and we already a semaphore in the struct usb_serial_port. The spinlocks _seems_ useless to me. -- Luiz Fernando N. Capitulino ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
