Messages in this thread | | | Subject | RE: [patch 3/3] Add tsi108 On Chip Ethernet device driver support | From | Arjan van de Ven <> | Date | Wed, 20 Sep 2006 10:45:57 +0200 |
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On Tue, 2006-09-19 at 15:39 +0800, Zang Roy-r61911 wrote:
> > > > > + spin_unlock_irq(&phy_lock); > > > + msleep(10); > > > + spin_lock_irq(&phy_lock); > > > + } > > > > hmm some places take phy_lock with disabling interrupts, while others > > don't. I sort of fear "the others" may be buggy.... are you sure those > > are ok? > Could you interpret your comments in detail? > Roy
Hi,
sorry for being unclear/too short in the review.
The phy_lock lock is sometimes taken as spin_lock() and sometimes as spin_lock_irq(). It looks likes it can be used in interrupt context, in which case the spin_lock_irq() version is correct and the places where spin_lock() is used would be a deadlock bug (just think what happens if the interrupt happens while spin_lock(&phy_lock) is helt, and the spinlock then again tries to take the lock!)
If there is no way this lock is used in interrupt context, then the spin_lock_irq() version is doing something which is not needed and also a bit expensive; so could be optimized.
But my impression is that the _irq() is needed. Also, please consider switching from spin_lock_irq() to spin_lock_irqsave() version instead; spin_unlock_irq() has some side effects (interrupts get enabled unconditionally) so it is generally safer to use spin_lock_irqsave()/spin_unlock_irqrestore() API.
If you have more questions please do not hesitate to ask!
Greetings, Arjan van de Ven -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com
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