From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3F6E9CCD194 for ; Wed, 15 Oct 2025 14:56:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CE87210E821; Wed, 15 Oct 2025 14:56:32 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="GgTqYcy0"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) by gabe.freedesktop.org (Postfix) with ESMTPS id A027D10E81E; Wed, 15 Oct 2025 14:56:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1760540190; x=1792076190; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=Jsijld0HCcmzHeyNrrPzpOL8hNoP4xsYnI/+09WsuAs=; b=GgTqYcy0vqZ4wPw/RU81xSNlMWoO+qn2PxBIb5SfaF+285jV3KMawSzT +mA4UuaUz+BL/ehkkxPEi4e8Zhe8d38FuW+wlAhSwrrm2Svq9y5yt0rRg R+fV2XTXHWzO8AaBFDfw4GDFMZBf8khovRDw8gVHN3GzVcOSMOQQ18bND o/co9hbzm1PIry2cdo9j/TkwAkQL3Y8AWzIt916qtinaeTpugKtTHA/RH hijRumnzEQ09aguokuTB4m/WhDKDaRVtzT7Yu1pmgngE9Dx4jOcGLgPIp dRpZf5UwcqVpptFSEeUXlsWy1GhNtfAf4f187ilW87E0zfZLE3Kwxmxuw w==; X-CSE-ConnectionGUID: JxZR/jxzQBui0AHldSz2LA== X-CSE-MsgGUID: sgED2IbFRk6AhT1TeOYjiw== X-IronPort-AV: E=McAfee;i="6800,10657,11583"; a="50285060" X-IronPort-AV: E=Sophos;i="6.19,231,1754982000"; d="scan'208";a="50285060" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Oct 2025 07:56:30 -0700 X-CSE-ConnectionGUID: 4W+A7xfTSruAkOMOTpOQSA== X-CSE-MsgGUID: ZeWDhKt1RvyWmdCWJ5tXfg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,231,1754982000"; d="scan'208";a="187487237" Received: from mjarzebo-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.100]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Oct 2025 07:56:25 -0700 From: Jani Nikula To: Gustavo Sousa , intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: Ankit Nautiyal , Dnyaneshwar Bhadane , Gustavo Sousa , Jouni =?utf-8?Q?H=C3=B6gander?= , Juha-pekka Heikkila , Luca Coelho , Lucas De Marchi , Matt Atwood , Matt Roper , Ravi Kumar Vodapalli , Sai Teja Pottumuttu , Shekhar Chauhan , Vinod Govindapillai Subject: Re: [PATCH 12/32] drm/i915/xe3p_lpd: Underrun debuggability and error codes/hints In-Reply-To: <20251015-xe3p_lpd-basic-enabling-v1-12-d2d1e26520aa@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20251015-xe3p_lpd-basic-enabling-v1-0-d2d1e26520aa@intel.com> <20251015-xe3p_lpd-basic-enabling-v1-12-d2d1e26520aa@intel.com> Date: Wed, 15 Oct 2025 17:56:22 +0300 Message-ID: <1b590289f8f24e4eb4da9b209503abe0eeba31dc@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, 15 Oct 2025, Gustavo Sousa wrote: > From: Sai Teja Pottumuttu > > Currently there is no way in the driver to classify the underruns into > different categories. Starting with Xe3p_LPD, we get two new registers > and some bits in existing registers which can help us categorise the > underruns and let us know possible reason behind the underrun. > > Bspec: 69111, 69561, 74411, 74412 > Signed-off-by: Sai Teja Pottumuttu > Signed-off-by: Gustavo Sousa > --- > drivers/gpu/drm/i915/display/intel_display_regs.h | 31 +++++++ > drivers/gpu/drm/i915/display/intel_fifo_underrun.c | 100 ++++++++++++++++++++- > 2 files changed, 130 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display_regs.h b/drivers/gpu/drm/i915/display/intel_display_regs.h > index 9d71e26a4fa2..9e2414b730db 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_regs.h > +++ b/drivers/gpu/drm/i915/display/intel_display_regs.h > @@ -882,6 +882,36 @@ > #define PIPE_MISC2_FLIP_INFO_PLANE_SEL_MASK REG_GENMASK(2, 0) /* tgl+ */ > #define PIPE_MISC2_FLIP_INFO_PLANE_SEL(plane_id) REG_FIELD_PREP(PIPE_MISC2_FLIP_INFO_PLANE_SEL_MASK, (plane_id)) > > +#define _UNDERRUN_DBG1_A 0x70064 > +#define _UNDERRUN_DBG1_B 0x71064 > +#define UNDERRUN_DBG1(pipe) _MMIO_PIPE(pipe, \ > + _UNDERRUN_DBG1_A, \ > + _UNDERRUN_DBG1_B) > +#define UNDERRUN_DBUF_BLOCK_NOT_VALID_MASK REG_GENMASK(29, 24) > +#define UNDERRUN_DBUF_BLOCK_NOT_VALID_PLANE_CURSOR REG_BIT(24) > +#define UNDERRUN_DDB_EMPTY_MASK REG_GENMASK(21, 16) > +#define UNDERRUN_DDB_EMPTY_PLANE_CURSOR REG_BIT(16) > +#define UNDERRUN_DBUF_NOT_FILLED_MASK REG_GENMASK(13, 8) > +#define UNDERRUN_DBUF_NOT_FILLED_PLANE_CURSOR REG_BIT(8) > +#define UNDERRUN_BELOW_WM0_MASK REG_GENMASK(5, 0) > +#define UNDERRUN_BELOW_WM0_PLANE_CURSOR REG_BIT(0) > + > +#define _UNDERRUN_DBG2_A 0x70068 > +#define _UNDERRUN_DBG2_B 0x71068 > +#define UNDERRUN_DBG2(pipe) _MMIO_PIPE(pipe, \ > + _UNDERRUN_DBG2_A, \ > + _UNDERRUN_DBG2_B) > +#define UNDERRUN_FRAME_LINE_COUNTERS_FROZEN REG_BIT(31) > +#define UNDERRUN_PIPE_FRAME_COUNT_MASK REG_GENMASK(30, 20) > +#define UNDERRUN_LINE_COUNT_MASK REG_GENMASK(19, 0) > + > +#define _FBC_DEBUG_STATUS_A 0x43220 > +#define _FBC_DEBUG_STATUS_B 0x43260 > +#define FBC_DEBUG_STATUS(pipe) _MMIO_PIPE(pipe, \ > + _FBC_DEBUG_STATUS_A, \ > + _FBC_DEBUG_STATUS_B) > +#define FBC_UNDERRUN_DECOMPRESSION REG_BIT(27) > + > #define DPINVGTT _MMIO(VLV_DISPLAY_BASE + 0x7002c) /* VLV/CHV only */ > #define DPINVGTT_EN_MASK_CHV REG_GENMASK(27, 16) > #define DPINVGTT_EN_MASK_VLV REG_GENMASK(23, 16) > @@ -1416,6 +1446,7 @@ > > #define GEN12_DCPR_STATUS_1 _MMIO(0x46440) > #define XELPDP_PMDEMAND_INFLIGHT_STATUS REG_BIT(26) > +#define XE3P_UNDERRUN_PKGC REG_BIT(21) > > #define FUSE_STRAP _MMIO(0x42014) > #define ILK_INTERNAL_GRAPHICS_DISABLE REG_BIT(31) > diff --git a/drivers/gpu/drm/i915/display/intel_fifo_underrun.c b/drivers/gpu/drm/i915/display/intel_fifo_underrun.c > index c2ce8461ac9e..753872ad28ed 100644 > --- a/drivers/gpu/drm/i915/display/intel_fifo_underrun.c > +++ b/drivers/gpu/drm/i915/display/intel_fifo_underrun.c > @@ -352,6 +352,101 @@ bool intel_set_pch_fifo_underrun_reporting(struct intel_display *display, > return old; > } > > +static void snprintf_underrun_planes(char *buf, size_t len, > + u32 underrun_dbg, u32 underrun_cursor) > +{ > + snprintf(buf, len, "%s%s%s%s%s%s", > + underrun_dbg & (underrun_cursor << 1) ? "[1]" : "", > + underrun_dbg & (underrun_cursor << 2) ? "[2]" : "", > + underrun_dbg & (underrun_cursor << 3) ? "[3]" : "", > + underrun_dbg & (underrun_cursor << 4) ? "[4]" : "", > + underrun_dbg & (underrun_cursor << 5) ? "[5]" : "", > + underrun_dbg & underrun_cursor ? "[C]" : ""); > +} I'm pretty sure this could be made cleaner by using seq_buf. > + > +static void xe3p_lpd_log_underrun(struct intel_display *display, > + enum pipe pipe) > +{ > + u32 underrun_dbg1; > + u32 underrun_dbg2; > + u32 fbc_debug_status; > + u32 dcpr_status; > + char planes[32]; > + > + /* > + * UNDERRUN_DBG1 reports the following things > + * 1. If DBUF block is not valid > + * 2. If DDB is empty > + * 3. If streamer could not completely fill DBUF at the end of vblank > + * 4. Each enabled plane/cursor below watermark 0 > + */ > + underrun_dbg1 = intel_de_read(display, UNDERRUN_DBG1(pipe)); > + intel_de_write(display, UNDERRUN_DBG1(pipe), underrun_dbg1); > + > + if (underrun_dbg1 & UNDERRUN_DBUF_BLOCK_NOT_VALID_MASK) { > + snprintf_underrun_planes(planes, sizeof(planes), underrun_dbg1, > + UNDERRUN_DBUF_BLOCK_NOT_VALID_PLANE_CURSOR); > + drm_err(display->drm, > + "Pipe %c FIFO underrun: DBUF block not valid for plane(s): %s\n", > + pipe_name(pipe), planes); > + } > + > + if (underrun_dbg1 & UNDERRUN_DDB_EMPTY_MASK) { > + snprintf_underrun_planes(planes, sizeof(planes), underrun_dbg1, > + UNDERRUN_DDB_EMPTY_PLANE_CURSOR); > + drm_err(display->drm, "Pipe %c FIFO underrun: DDB empty for plane(s): %s\n", > + pipe_name(pipe), planes); > + } > + > + if (underrun_dbg1 & UNDERRUN_DBUF_NOT_FILLED_MASK) { > + snprintf_underrun_planes(planes, sizeof(planes), underrun_dbg1, > + UNDERRUN_DBUF_NOT_FILLED_PLANE_CURSOR); > + drm_err(display->drm, "Pipe %c FIFO underrun: DBUF not filled for plane(s): %s\n", > + pipe_name(pipe), planes); > + } > + > + if (underrun_dbg1 & UNDERRUN_BELOW_WM0_MASK) { > + snprintf_underrun_planes(planes, sizeof(planes), underrun_dbg1, > + UNDERRUN_BELOW_WM0_PLANE_CURSOR); > + drm_err(display->drm, "Pipe %c FIFO underrun: Below watermark 0 on plane(s): %s\n", > + pipe_name(pipe), planes); > + } > + > + /* > + * UNDERRUN_DBG2 reports the frame count and line count when the underrun started. > + */ > + underrun_dbg2 = intel_de_read(display, UNDERRUN_DBG2(pipe)); > + if (underrun_dbg2 & UNDERRUN_FRAME_LINE_COUNTERS_FROZEN) { > + intel_de_write(display, UNDERRUN_DBG2(pipe), UNDERRUN_FRAME_LINE_COUNTERS_FROZEN); > + drm_err(display->drm, "Pipe %c FIFO underrun: Frame count: %u, Line count: %u\n", > + pipe_name(pipe), > + REG_FIELD_GET(UNDERRUN_PIPE_FRAME_COUNT_MASK, underrun_dbg2), > + REG_FIELD_GET(UNDERRUN_LINE_COUNT_MASK, underrun_dbg2)); > + } > + > + /* > + * FBC_DEBUG_STATUS's FBC_UNDERRUN_DECOMPRESSION indicates if FBC was > + * decompressing when underrun got triggered. > + */ > + fbc_debug_status = intel_de_read(display, FBC_DEBUG_STATUS(pipe)); > + if (fbc_debug_status & FBC_UNDERRUN_DECOMPRESSION) { > + intel_de_write(display, FBC_DEBUG_STATUS(pipe), FBC_UNDERRUN_DECOMPRESSION); > + drm_err(display->drm, "Pipe %c FIFO underrun: FBC decompression\n", > + pipe_name(pipe)); > + } > + > + /* > + * GEN12_DCPR_STATUS_1's XE3P_UNDERRUN_PKGC, indicates that underrun started > + * while pkgc was blocking memory. > + */ > + dcpr_status = intel_de_read(display, GEN12_DCPR_STATUS_1); > + if (dcpr_status & XE3P_UNDERRUN_PKGC) { > + intel_de_write(display, GEN12_DCPR_STATUS_1, XE3P_UNDERRUN_PKGC); > + drm_err(display->drm, "Pipe %c FIFO underrun: Pkgc blocking memory\n", > + pipe_name(pipe)); > + } > +} > + > /** > * intel_cpu_fifo_underrun_irq_handler - handle CPU fifo underrun interrupt > * @display: display device instance > @@ -378,7 +473,10 @@ void intel_cpu_fifo_underrun_irq_handler(struct intel_display *display, > if (intel_set_cpu_fifo_underrun_reporting(display, pipe, false)) { > trace_intel_cpu_fifo_underrun(display, pipe); > > - drm_err(display->drm, "CPU pipe %c FIFO underrun\n", pipe_name(pipe)); > + if (DISPLAY_VER(display) >= 35) > + xe3p_lpd_log_underrun(display, pipe); > + else > + drm_err(display->drm, "CPU pipe %c FIFO underrun\n", pipe_name(pipe)); > } > > intel_fbc_handle_fifo_underrun_irq(display); -- Jani Nikula, Intel