Le Thu, 7 Feb 2008 18:19:07 +0200, "Ramagudi Naziir" <naziirr@xxxxxxxxx> a écrit : > in iw_handler.h... and tried to understand why it is a problem.. This is a problem because copy_to_user() and copy_from_user() can block. So you're not allowed to use them in an atomic context (interrupt handler or tasklet). From Linux Device Drivers, chapter 3, speaking about copy_to_user() and copy_from_user() : « Although these functions behave like normal memcpy functions, a little extra care must be used when accessing user space from kernel code. The user pages being addressed might not be currently present in memory, and the virtual memory sub- system can put the process to sleep while the page is being transferred into place. This happens, for example, when the page must be retrieved from swap space. » Sincerly, Thomas -- Thomas Petazzoni, Free Electrons Free Embedded Linux Training Materials on http://free-electrons.com/training (More than 1500 pages!)
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