From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754782AbdBPAIz (ORCPT ); Wed, 15 Feb 2017 19:08:55 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754044AbdBOXQO (ORCPT ); Wed, 15 Feb 2017 18:16:14 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alex Deucher" Date: Wed, 15 Feb 2017 22:41:40 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 127/306] drm/radeon: change vblank_time's calculation method to reduce computational error. In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alex Deucher commit 02cfb5fccb0f9f968f0e208d89d9769aa16267bc upstream. Ported from Rex's amdgpu change. Signed-off-by: Alex Deucher Signed-off-by: Ben Hutchings --- drivers/gpu/drm/radeon/r600_dpm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/drivers/gpu/drm/radeon/r600_dpm.c +++ b/drivers/gpu/drm/radeon/r600_dpm.c @@ -155,19 +155,20 @@ u32 r600_dpm_get_vblank_time(struct rade struct drm_device *dev = rdev->ddev; struct drm_crtc *crtc; struct radeon_crtc *radeon_crtc; - u32 line_time_us, vblank_lines; + u32 vblank_in_pixels; u32 vblank_time_us = 0xffffffff; /* if the displays are off, vblank time is max */ if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) { list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { radeon_crtc = to_radeon_crtc(crtc); if (crtc->enabled && radeon_crtc->enabled && radeon_crtc->hw_mode.clock) { - line_time_us = (radeon_crtc->hw_mode.crtc_htotal * 1000) / - radeon_crtc->hw_mode.clock; - vblank_lines = radeon_crtc->hw_mode.crtc_vblank_end - - radeon_crtc->hw_mode.crtc_vdisplay + - (radeon_crtc->v_border * 2); - vblank_time_us = vblank_lines * line_time_us; + vblank_in_pixels = + radeon_crtc->hw_mode.crtc_htotal * + (radeon_crtc->hw_mode.crtc_vblank_end - + radeon_crtc->hw_mode.crtc_vdisplay + + (radeon_crtc->v_border * 2)); + + vblank_time_us = vblank_in_pixels * 1000 / radeon_crtc->hw_mode.clock; break; } }