From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757358Ab0IRTSg (ORCPT ); Sat, 18 Sep 2010 15:18:36 -0400 Received: from kroah.org ([198.145.64.141]:43914 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757251Ab0IRTQ1 (ORCPT ); Sat, 18 Sep 2010 15:16:27 -0400 X-Mailbox-Line: From gregkh@clark.site Sat Sep 18 12:13:07 2010 Message-Id: <20100918191307.248377322@clark.site> User-Agent: quilt/0.48-11.2 Date: Sat, 18 Sep 2010 12:13:34 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alex Deucher , Dave Airlie Subject: [116/129] drm/radeon/kms: force legacy pll algo for RV515 LVDS In-Reply-To: <20100918191317.GA11386@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Alex Deucher commit 0d9958b18e10d7426d94cc3dd024920a40db3ee2 upstream. There has been periodic evidence that LVDS, on at least some panels, prefers the dividers selected by the legacy pll algo. This patch forces the use of the legacy pll algo on RV515 LVDS panels. The old behavior (new pll algo) can be selected by setting the new_pll module parameter to 1. Signed-off-by: Alex Deucher Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/drivers/gpu/drm/radeon/atombios_crtc.c +++ b/drivers/gpu/drm/radeon/atombios_crtc.c @@ -527,6 +527,20 @@ static u32 atombios_adjust_pll(struct dr pll->algo = PLL_ALGO_LEGACY; pll->flags |= RADEON_PLL_PREFER_CLOSEST_LOWER; } + /* There is some evidence (often anecdotal) that RV515 LVDS + * (on some boards at least) prefers the legacy algo. I'm not + * sure whether this should handled generically or on a + * case-by-case quirk basis. Both algos should work fine in the + * majority of cases. + */ + if ((radeon_encoder->active_device & (ATOM_DEVICE_LCD_SUPPORT)) && + (rdev->family == CHIP_RV515)) { + /* allow the user to overrride just in case */ + if (radeon_new_pll == 1) + pll->algo = PLL_ALGO_NEW; + else + pll->algo = PLL_ALGO_LEGACY; + } } else { if (encoder->encoder_type != DRM_MODE_ENCODER_DAC) pll->flags |= RADEON_PLL_NO_ODD_POST_DIV;