From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Copeland Date: Thu, 7 Nov 2013 09:20:04 -0500 Subject: [ath9k-devel] ath5k tx completion In-Reply-To: References: <20131106134108.GB5022@localhost> Message-ID: <20131107142004.GA15085@localhost> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On Wed, Nov 06, 2013 at 09:17:46AM -0800, Adrian Chadd wrote: > The TL;DR version - you need to keep the the final descriptor around > for each hardware queue. The legacy madwifi/freebsd way of doing it > was to keep the last descriptor that was handled. This wasn't enough. > It needs to be per TX queue. You also must never program TxDP after > you've programmed it once - you can only program it again after you've > completely torn down TX DMA for the particular queue. This is a goldmine -- thank you for taking the time to write it up! I believe we can clean up ath5k's transmit loop a lot now... > * read-and-clear bugs > * PHY register read problems, and why ANI may occasionally look whacked One thing at a time for me... but do we even want to know? :) -- Bob Copeland %% www.bobcopeland.com