Re: [PATCH v2 04/10] i2c: rcar: remove spinlock

[Sergei Shtylyov]

Hello.

On 11/12/2015 5:31 PM, Wolfram Sang wrote:


From: Wolfram Sang 

After making sure to reinit the HW and clear interrupts in the timeout
case, we know that interrupts are always disabled in the sections
protected by the spinlock.


   What about SMP? Spinlocks are mostly necessary for the SMP support, their 
tole isn't limited to disabling interrupts...



Thus, we can simply remove it which is a
preparation for further refactoring. While here, rename the timeout
variable to time_left which is way more readable.

Signed-off-by: Wolfram Sang 


[...]

MBR, Sergei

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Re: [PATCH v2 04/10] i2c: rcar: remove spinlock

[Wolfram Sang]

On Thu, Nov 12, 2015 at 06:04:27PM +0300, Sergei Shtylyov wrote:
> Hello.
> 
> On 11/12/2015 5:31 PM, Wolfram Sang wrote:
> 
> >From: Wolfram Sang 
> >
> >After making sure to reinit the HW and clear interrupts in the timeout
> >case, we know that interrupts are always disabled in the sections
> >protected by the spinlock.
> 
>What about SMP? Spinlocks are mostly necessary for the SMP support, their
> tole isn't limited to disabling interrupts...

We have per-adapter locks in the core. Once a transfer is started, you
can't access the adapter unless the transfer is finished. But then, all
interrupts are off again.



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