Re: [alsa-devel] [PATCH 4/4] ASoC: fsl: make fsl_ssi driver compilable on ARM/IMX

Russell King - ARM Linux wrote:

Is your readl() or readl_be() unordered then?

Yes. At least, it sure looks like it is.

Wouldn't that be buggy between coherent DMA accesses and accessing, eg, a PCI peripheral to enable or read DMA status?

I think so.

We almost never use readl. I see that it is used in some places, but honestly I can't see how it can be valid. For instance, the mpic driver uses it in mpic_startup_ht_interrupt(). I don't understand how that's valid, since there's nothing preventing the readl() from happening *before* the writeb.

I'll have to ask around, because I'm sure I'm missing something.