Re: [spi-devel-general] Re: SPI

[Vitaly W. <vw...@ru...>]

David Brownell wrote:

>>You need to create the semaphore to protect 
>>the global 'buf', so if you have two controllers on the same board, you
>>would not perform two simultaneous transfers with these controllers,
>>right ?
>>    
>>
>
>Yes, there IS a semaphore:
>
>+int spi_write_then_read(...)
>+{
>+       static DECLARE_MUTEX(lock);
>+       ...
>+       down(&lock);
>+       ...
>+       up(&lock);
>+       return status;
>+}
>
>  
>
So spi_write_then_read() can't ever be called from an interrupt context, 
right?

Vitaly