From 3288bff62342281c6c6cdd2df6e6fc19afe98498 Mon Sep 17 00:00:00 2001 From: =?utf8?q?=C3=89ric=20Piel?= Date: Wed, 19 Dec 2012 13:03:13 +0100 Subject: [PATCH] staging: comedi: fix minimum AO period for NI 625x and NI 628x MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 34b55d8c48f4f76044d8f4d6ec3dc786cf210312 upstream. The minimum period was set to 357 ns, while the divider for these boards is 50 ns. This prevented to output at maximum speed as ni_ao_cmdtest() would return 357 but would not accept it. Not sure why it was set to 357 ns (this was done before the git history, which starts 5 years ago). My guess is that it comes from reading the specification stating a 2.8 MHz rate (~ 357 ns). The latest specification states a 2.86 MHz rate (~ 350 ns), which makes a lot more sense. Tested on a pci-6251. Signed-off-by: Éric Piel Acked-By: Ian Abbott Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: drop hunk for a board that's not listed] Signed-off-by: Ben Hutchings --- Reading git-format-patch failed