Re: [PATCH v3 1/3] powerpc/512x: add LocalPlus Bus FIFO device driver

From: Alexander Popov
Date: Tue Sep 29 2015 - 02:30:57 EST

On 28.09.2015 16:18, Timur Tabi wrote:
> Alexander Popov wrote:
>> The only question I have: why calling dma_unmap_single() from within
>> a spinlock is a bad practice?
> I don't know, but usually functions that allocate or free memory cannot be
> called from within a spinlock. You need to check that. Since the MPC5121
> is a single-core CPU, you might not notice if you're doing something wrong.

I've double-checked the code and LDD and don't see any reason to avoid
calling dma_unmap_single() from interrupt context and within spinlock.

Please correct me if I'm wrong.

Best regards,
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at