Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943251AbcJ2ORb (ORCPT ); Sat, 29 Oct 2016 10:17:31 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49522 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S942447AbcJ2Nv6 (ORCPT ); Sat, 29 Oct 2016 09:51:58 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tvrtko Ursulin , Lyude , Maarten Lankhorst , Paulo Zanoni , Jani Nikula Subject: [PATCH 4.8 026/125] drm/i915/gen9: fix plane_blocks_per_line on watermarks calculations Date: Sat, 29 Oct 2016 09:49:04 -0400 Message-Id: <20161029134948.300726363@linuxfoundation.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161029134947.232372651@linuxfoundation.org> References: <20161029134947.232372651@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4208 Lines: 111 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Zanoni commit cf6c525a31fac11b0775b8c06c00a508c6356d9b upstream. The confusing thing is that plane_blocks_per_line is listed as part of the method 2 calculation but is also used for other things. We calculated it in two different places and different ways: one inside skl_wm_method2() and the other inside skl_compute_plane_wm(). The skl_wm_method2() implementation is the one that matches the specification. With this patch we fix the skl_compute_plane_wm() calculation and just pass it as a parameter to skl_wm_method2(). We also take care to not modify the value of plane_bytes_per_line since we're going to rely on it having a correct value in later patches. This should affect the watermarks for Linear and Y-tiled. >From my analysis, it looks like the two plane_blocks_per_line variables got out of sync on 0fda65680e92, but we can't really say that commit was a regression, it looks like just an incomplete fix. There's always the possibility that 0fda65680e92 matched our specification at that time, and then later the specification changed. v2: Try to add a "Fixes" tag (Maarten). Fixes: 0fda65680e92 ("drm/i915/skl: Update watermarks for Y tiling") Cc: Tvrtko Ursulin Reviewed-by: Lyude Reviewed-by: Maarten Lankhorst Signed-off-by: Paulo Zanoni Link: http://patchwork.freedesktop.org/patch/msgid/1474578035-424-7-git-send-email-paulo.r.zanoni@intel.com (cherry picked from commit 7a1a8aed67e0a60772defe3f6499eb340da48634) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_pm.c | 39 +++++++++++++++------------------------ 1 file changed, 15 insertions(+), 24 deletions(-) --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3475,30 +3475,14 @@ static uint32_t skl_wm_method1(uint32_t } static uint32_t skl_wm_method2(uint32_t pixel_rate, uint32_t pipe_htotal, - uint32_t horiz_pixels, uint8_t cpp, - uint64_t tiling, uint32_t latency, - uint32_t y_min_scanlines) + uint32_t latency, uint32_t plane_blocks_per_line) { uint32_t ret; - uint32_t plane_bytes_per_line, plane_blocks_per_line; uint32_t wm_intermediate_val; if (latency == 0) return UINT_MAX; - plane_bytes_per_line = horiz_pixels * cpp; - - if (tiling == I915_FORMAT_MOD_Y_TILED || - tiling == I915_FORMAT_MOD_Yf_TILED) { - plane_bytes_per_line *= y_min_scanlines; - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); - plane_blocks_per_line /= y_min_scanlines; - } else if (tiling == DRM_FORMAT_MOD_NONE) { - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512) + 1; - } else { - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); - } - wm_intermediate_val = latency * pixel_rate; ret = DIV_ROUND_UP(wm_intermediate_val, pipe_htotal * 1000) * plane_blocks_per_line; @@ -3587,17 +3571,24 @@ static int skl_compute_plane_wm(const st y_min_scanlines = 4; } + plane_bytes_per_line = width * cpp; + if (fb->modifier[0] == I915_FORMAT_MOD_Y_TILED || + fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED) { + plane_blocks_per_line = + DIV_ROUND_UP(plane_bytes_per_line * y_min_scanlines, 512); + plane_blocks_per_line /= y_min_scanlines; + } else if (fb->modifier[0] == DRM_FORMAT_MOD_NONE) { + plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512) + + 1; + } else { + plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); + } + method1 = skl_wm_method1(plane_pixel_rate, cpp, latency); method2 = skl_wm_method2(plane_pixel_rate, cstate->base.adjusted_mode.crtc_htotal, - width, - cpp, - fb->modifier[0], latency, - y_min_scanlines); - - plane_bytes_per_line = width * cpp; - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); + plane_blocks_per_line); if (fb->modifier[0] == I915_FORMAT_MOD_Y_TILED || fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED) {