From patchwork Thu Aug 29 22:00:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gustavo Sousa X-Patchwork-Id: 13783962 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 4E173CA0EC0 for ; Thu, 29 Aug 2024 22:04:06 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E1F6510E797; Thu, 29 Aug 2024 22:04:05 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="al+v5gVY"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id E34C510E766 for ; Thu, 29 Aug 2024 22:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724969038; x=1756505038; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=+FX3SaOnyBnwZfaIejpKnx9BcjJNcW0bkz/n+wbneeg=; b=al+v5gVYFsw2JOpZAVmhbLyT6WKsTl9+lQFnoxivsA6aLNNTbdvVBwKc cEw6kYryBb7vLWJQ3MWHYyXxY+/xJv8MSn13YXpgrbRMvUSBTE+CPSj9Q 9tI0mq6fUFO62IUcd6PGzxZwLTrwJmBB4gWpBEJA76hN/7ok/3xWL2xzc F2JviaZpMNEqlcJTmhS0D8yHM92aisPxpEU+r/g0Geai76X3pnCqw/bpF zyvlksSMAmZ2uINjYTBIHH+mttPT5axxIalZC9ucSNK1YBzhfiPmyepAU rgm/7GCSypx0jvLNFBa7zLN7rnWQIeNzs5hVBdDXN4shRNqepeYhna1uW Q==; X-CSE-ConnectionGUID: +qLoJzjjSP67EyH7c5l8pQ== X-CSE-MsgGUID: w09QTwuXQHKpKywc8qYMZA== X-IronPort-AV: E=McAfee;i="6700,10204,11179"; a="27356221" X-IronPort-AV: E=Sophos;i="6.10,186,1719903600"; d="scan'208";a="27356221" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Aug 2024 15:01:47 -0700 X-CSE-ConnectionGUID: oC9+6GeMT9K6KPABs3GIBg== X-CSE-MsgGUID: S2QBnhDIRAOH5Gimey94VA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,186,1719903600"; d="scan'208";a="68541479" Received: from djiang5-mobl3.amr.corp.intel.com (HELO gjsousa-mobl2.intel.com) ([10.125.108.19]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Aug 2024 15:01:46 -0700 From: Gustavo Sousa To: intel-gfx@lists.freedesktop.org Subject: [PATCH 3/4] drm/i915/display: Do not use ids from enum pipe in TP_printk() Date: Thu, 29 Aug 2024 19:00:46 -0300 Message-ID: <20240829220106.80449-4-gustavo.sousa@intel.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240829220106.80449-1-gustavo.sousa@intel.com> References: <20240829220106.80449-1-gustavo.sousa@intel.com> MIME-Version: 1.0 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" Because much of kernel tracepoints is implemented at the C preprocessor level, C identifiers used in TP_printk() are saved verbatim in the event format, even when they represent compile-time constant values. As an example, we can look at the format for the intel_pipe_enable event: # cat /sys/kernel/debug/tracing/events/i915/intel_pipe_enable/format | grep '^print fmt' print fmt: "dev %s, pipe %c enable, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u", __get_str(dev), REC->pipe_name, REC->frame[PIPE_A], REC->scanline[PIPE_A], REC->frame[PIPE_B], REC->scanline[PIPE_B], REC->frame[PIPE_C], REC->scanline[PIPE_C] We see that PIPE_A, PIPE_B and PIPE_C are pasted directly in the format. Because tools that interact with kernel tracepoints don't know about those ids, they'll endup failing to parse the format or produce corrupted output. For example, we can see below that trace-cmd repeats PIPE_A's frame/scanline counts for all pipes (probably because it evaluates unknown ids as zero): $ trace-cmd report -F intel_pipe_enable | tail -n5 testdisplay-8616 [000] 22048.276758: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=861, scanline=480, pipe B: frame=861, scanline=480, pipe C: frame=861, scanline=480 testdisplay-8616 [001] 22048.490287: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=867, scanline=480, pipe B: frame=867, scanline=480, pipe C: frame=867, scanline=480 testdisplay-8616 [003] 22048.700181: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=872, scanline=400, pipe B: frame=872, scanline=400, pipe C: frame=872, scanline=400 testdisplay-8616 [002] 22049.054220: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=881, scanline=2170, pipe B: frame=881, scanline=2170, pipe C: frame=881, scanline=2170 testdisplay-8616 [002] 22049.166851: intel_pipe_enable: dev 0000:00:02.0, pipe B enable, pipe A: frame=887, scanline=1632, pipe B: frame=887, scanline=1632, pipe C: frame=887, scanline=1632 , while in fact we have different values for each pipe, which can be confirmed with the raw view of the events: $ trace-cmd report -R -F intel_pipe_enable | tail -n5 testdisplay-8616 [000] 22048.276758: intel_pipe_enable: dev=0000:00:02.0 frame=ARRAY[5d, 03, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] scanline=ARRAY[e0, 01, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] pipe_name=A testdisplay-8616 [001] 22048.490287: intel_pipe_enable: dev=0000:00:02.0 frame=ARRAY[63, 03, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] scanline=ARRAY[e0, 01, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] pipe_name=A testdisplay-8616 [003] 22048.700181: intel_pipe_enable: dev=0000:00:02.0 frame=ARRAY[68, 03, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] scanline=ARRAY[90, 01, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] pipe_name=A testdisplay-8616 [002] 22049.054220: intel_pipe_enable: dev=0000:00:02.0 frame=ARRAY[71, 03, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] scanline=ARRAY[7a, 08, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] pipe_name=A testdisplay-8616 [002] 22049.166851: intel_pipe_enable: dev=0000:00:02.0 frame=ARRAY[77, 03, 00, 00, 01, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] scanline=ARRAY[60, 06, 00, 00, 39, 04, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00] pipe_name=B To fix that, we need a fix that looks more like a hack: use macros that result to integer constants instead of enum pipe values. This fixes the issue, but could break if, for whatever unlikely reason, the underlying values in the enum are changed. In the future, we should find a better way to handle this, but for now, the hack took care of the job: $ trace-cmd report -F intel_pipe_enable | tail -n5 testdisplay-9224 [003] 24324.455375: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=1103, scanline=480, pipe B: frame=0, scanline=0, pipe C: frame=0, scanline=0 testdisplay-9224 [002] 24324.669845: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=1109, scanline=480, pipe B: frame=0, scanline=0, pipe C: frame=0, scanline=0 testdisplay-9224 [003] 24324.900105: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=1115, scanline=31, pipe B: frame=0, scanline=0, pipe C: frame=0, scanline=0 testdisplay-9224 [002] 24325.256408: intel_pipe_enable: dev 0000:00:02.0, pipe A enable, pipe A: frame=1124, scanline=2171, pipe B: frame=0, scanline=0, pipe C: frame=0, scanline=0 testdisplay-9224 [003] 24325.380789: intel_pipe_enable: dev 0000:00:02.0, pipe B enable, pipe A: frame=1131, scanline=979, pipe B: frame=1, scanline=1082, pipe C: frame=0, scanline=0 Signed-off-by: Gustavo Sousa Reviewed-by: Matt Roper --- .../drm/i915/display/intel_display_trace.h | 27 ++++++++++++------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_trace.h b/drivers/gpu/drm/i915/display/intel_display_trace.h index ec2ab6fb743d..759b985c84a9 100644 --- a/drivers/gpu/drm/i915/display/intel_display_trace.h +++ b/drivers/gpu/drm/i915/display/intel_display_trace.h @@ -22,6 +22,15 @@ #define __dev_name_i915(i915) dev_name((i915)->drm.dev) #define __dev_name_kms(obj) dev_name((obj)->base.dev->dev) +/* + * Using identifiers from enum pipe in TP_printk() will confuse tools that + * parse /sys/kernel/debug/tracing/{xe,i915}//format. So we use CPP + * macros instead. + */ +#define _TRACE_PIPE_A 0 +#define _TRACE_PIPE_B 1 +#define _TRACE_PIPE_C 2 + TRACE_EVENT(intel_pipe_enable, TP_PROTO(struct intel_crtc *crtc), TP_ARGS(crtc), @@ -45,9 +54,9 @@ TRACE_EVENT(intel_pipe_enable, TP_printk("dev %s, pipe %c enable, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u", __get_str(dev), __entry->pipe_name, - __entry->frame[PIPE_A], __entry->scanline[PIPE_A], - __entry->frame[PIPE_B], __entry->scanline[PIPE_B], - __entry->frame[PIPE_C], __entry->scanline[PIPE_C]) + __entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A], + __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B], + __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C]) ); TRACE_EVENT(intel_pipe_disable, @@ -74,9 +83,9 @@ TRACE_EVENT(intel_pipe_disable, TP_printk("dev %s, pipe %c disable, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u", __get_str(dev), __entry->pipe_name, - __entry->frame[PIPE_A], __entry->scanline[PIPE_A], - __entry->frame[PIPE_B], __entry->scanline[PIPE_B], - __entry->frame[PIPE_C], __entry->scanline[PIPE_C]) + __entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A], + __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B], + __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C]) ); TRACE_EVENT(intel_crtc_flip_done, @@ -204,9 +213,9 @@ TRACE_EVENT(intel_memory_cxsr, TP_printk("dev %s, cxsr %s->%s, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u", __get_str(dev), str_on_off(__entry->old), str_on_off(__entry->new), - __entry->frame[PIPE_A], __entry->scanline[PIPE_A], - __entry->frame[PIPE_B], __entry->scanline[PIPE_B], - __entry->frame[PIPE_C], __entry->scanline[PIPE_C]) + __entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A], + __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B], + __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C]) ); TRACE_EVENT(g4x_wm,