Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

David Miller [off-list ref] writes:

From: Måns Rullgård <redacted>
Date: Wed, 11 Nov 2015 19:35:05 +0000

quoted

quoted

I don't think it's silly at all.

I'm sure I read somewhere that the time spent spinning on a lock should
be kept as small as possible.

quoted

And unless you can measure it making a difference, don't knock the idea.

I tried using netif_tx_lock() in the IRQ handler instead, and it locked
up solid.  Clearly that was the wrong thing to do.

Oh that's right, it's a BH lock not an IRQ one.

Yet another argument for doing everything in ->poll(), thus making all
operations outside of NAPI scheduling run in software interrupt
context, and therefore being able to make use of the TXQ lock for
this.

Well, I tried calling the DMA restart function from NAPI poll under
netif_tx_lock().  Now it works only as long as there is incoming
traffic.

-- 
Måns Rullgård
mans@mansr.com