[PATCH] B43: Handle DMA RX descriptor underrun

[Michael Büsch]

On Sun, 5 May 2013 18:31:20 +0200
Rafał Miłecki <zajec5 at gmail.com> wrote:

> Still worth considering is my previous e-mail. Why writing (for
> example) 1 to RXSTOPINDEX doesn't stop firmware from using slot 1?

What makes you think this register does not work?

Do you write a 1 to the register, or do you mean "the offset that
corresponds to slot 1"?

> Can it be because it's "too late"? For example:
> 1) Firmware writes to slot 0, changes "curr descr" to 1
> 2) Firmware grabs slot 1
> 3) Firmware generates IRQ
> 4) Driver reads slot 0
> 5) Driver writes RX stop index 1

The stop index is the index that the firmware does _not_ write to.
If you set it _after_ it already wrote, you clearly are too late (for
this ring wrapping).

-- 
Michael
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