console spin_lock

From: James Simmons (jsimmons@suse.com)
Date: Tue Jan 16 2001 - 19:05:38 EST


Some time ago a intel i810 framebuffer driver was written. It only worked
for 2.2.X. With 2.4.X a spinlock is used in the upper layers of the
console system. Sooner or later we are going to run into the situtation
where we will have graphics hardware which has no vga core and wih be
purely DMA/irq based (i.e i810). In this case using the current
console_lock will block the driver itself. I have thought about a
possible solution. A semaphore can't be used since their is a spin_lock
in the console_softirq. Since this is in a interrupt context a
semaphore can't be used. Another idea was to do a

void get_vc_lock(void)
{
        while (test_and_set_bit(0, &vc_var))
                ;
}

Any better ideas?

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This archive was generated by hypermail 2b29 : Tue Jan 23 2001 - 21:00:14 EST