On Thu, 31 Jul 2003, Bertin Philippe wrote: > 'Llo All, > > I have a (kernel reader newbie) question : > In kernel version's 2.4.20's usb.c, function usb_get_configuration(), one > sees buffer be kmalloc'ed. Is there a reason why not to just have it > declared on the stack (as a char[8]) ? Maybe hardware alignment ? If that > last is not the case, then this kmalloc looks overkill, doesn't it ? Or is > there another good reason ? > Thanks,
There is another good reason. Since buffer is used for I/O, it needs to be addressable via DMA. On some architectures, stack-based and statically allocated memory cannot be used for DMA. Only dynamically allocated memory is suitable. Alan Stern ------------------------------------------------------- This SF.Net email sponsored by: Free pre-built ASP.NET sites including Data Reports, E-commerce, Portals, and Forums are available now. Download today and enter to win an XBOX or Visual Studio .NET. http://aspnet.click-url.com/go/psa00100003ave/direct;at.aspnet_072303_01/01 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
