From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Wed, 03 Aug 2005 00:40:37 +0200
From: Hannes Mayer <h.mayer@domain.hid>
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Subject: [Adeos-main] do_gettimeofday in ADEOS ISR
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To: adeos-main@gna.org

Hi all!

I was just wondering if calling do_gettimeofday in an ADEOS interrupt
handler might cause any problems whatsoever ?

My ISR:
flags = adeos_critical_enter (NULL);
[...]
do_gettimeofday()
[...]
adeos_critical_exit (flags);

I saw that the code for do_gettimeofday is different in kernel 2.4 and
kernel 2.6:

Kernel 2.4:
void do_gettimeofday(struct timeval *tv) {
[...]
read_lock_irqsave(&xtime_lock, flags);
[...]
read_unlock_irqrestore(&xtime_lock, flags);

Kernel 2.6:
void do_gettimeofday(struct timeval *tv) {
[...]
do {
[...]
seq = read_seqbegin(&xtime_lock);
[...]
} while (read_seqretry(&xtime_lock, seq));

Well, read_lock_irqsave in 2.4 looks like a possible source for trouble,
while read_seqbegin in 2.6 doesn't do anything with interrupts, right ?

Thanks for all comments!

Best regards,
Hannes.