[PATCH] cs5535-mfgpt: reuse timers that have never been set up
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From: Jens Rottmann on 8 Jul 2010 11:20 cs5535-mfgpt: reuse timers that have never been set up The MFGPT hardware may be set up only once, therefore cs5535_mfgpt_free_timer() didn't re-set the timer's "avail" bit. However if a timer is freed before it has actually been in use then it may be made available again. Signed-off-by: Jens Rottmann <JRottmann(a)LiPPERTEmbedded.de> --- Hi Andres, Jens wrote: > Andres wrote: >> Jens wrote: >>> cs5535_mfgpt_init() doesn't free up the timer in the error path >> >> Yeah, we can't really free the timer, unfortunately. >> It actually might not be a bad idea to reverse the code so that the >> IRQ allocation happens first, since we can clean that up if mfgpt >> allocation fails. > > [...] I guess for reversing the order we'd have to split both > cs5535_mfgpt_alloc_timer() and cs5535_mfgpt_setup_irq() into two parts [...] > Maybe cs5535_mfgpt_free_timer() can be made more intelligent to set > mfgpt->avail again if the hardware isn't actually in a non-reversible state > yet [...] As you can see I did just that. What do you think? Cheers, Jens --- linux-2.6.35-rc4/drivers/misc/cs5535-mfgpt.c +++ mfgpt_reuse_timers/drivers/misc/cs5535-mfgpt.c @@ -211,6 +211,17 @@ */ void cs5535_mfgpt_free_timer(struct cs5535_mfgpt_timer *timer) { + unsigned long flags; + uint16_t val; + + /* timer can be made available again only if never set up */ + val = cs5535_mfgpt_read(timer, MFGPT_REG_SETUP); + if (!(val & MFGPT_SETUP_SETUP)) { + spin_lock_irqsave(&timer->chip->lock, flags); + __set_bit(timer->nr, timer->chip->avail); + spin_unlock_irqrestore(&timer->chip->lock, flags); + } + kfree(timer); } EXPORT_SYMBOL_GPL(cs5535_mfgpt_free_timer); _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |