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 E39B6CA9EDE for ; Mon, 12 Oct 2026 14:36:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8537E10F16A; Mon, 12 Oct 2026 14:36:25 +0000 (UTC) Received: from host3.o27bbn.ondsl.gr (host3.o27bbn.ondsl.gr [79.129.74.131]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8D21210F004; Mon, 12 Oct 2026 11:11:30 +0000 (UTC) Received: from mail.e-psn.eu (cluster-localnode [10.200.210.1]) by mail.e-psn.eu (Postfix) with ESMTPA id 3033E3842BC7; Mon, 12 Oct 2026 11:11:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=e-psn.eu; s=default; t=1791803488; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+fh4+TCDGqb+p1deMexiH2CF0uJZ6hXG1cZ+wkTnl+Y=; b=pdjVKaMBO6v6SiMg+NTkQeeIgnNkJbnkmmOhm3vl0u96JAclj74hMaB+S7HOn7eb2EgJ/S t+evWk5VoTUmJvRkYNRGEQ+Dqm+IbgdmI6aYL/aqgghicFK2AONfhn6HOp8gmQ/x1aLJpI D9UphRF+Z1319a7sNsHODZjKfG9qc69FVE8JbcD/ThtZl6i6OYdr8KKZ5U0GOH23IJFKiU qQIEgND9Ghfbg6AWvKwnKUX8f3AG2HvxB/JkNciahhzPYnc5uMtClWC4VohNNgd4oULoVE YJTkh9gDut6rbxmkjAJuWhG7LKVZpeo9JnaMmm3ZOBBng/HJ1O+AtuJTXMJ3kQ== MIME-Version: 1.0 Date: Mon, 12 Oct 2026 14:11:28 +0300 From: Constantinos Chalkias To: sashiko-reviews@lists.linux.dev Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/xe/hwmon: refresh Battlemage thermal telemetry under force-wake Mail-Reply-To: cch@e-psn.eu In-Reply-To: References: <20261012104245.2108030-1-cch@e-psn.eu> Message-ID: <4f2e9bd1da1964bb014e5b3fa4fe83eb@e-psn.eu> X-Sender: cch@e-psn.eu Organization: E-PSN Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Flag-Threshold: 6 X-Mailman-Approved-At: Mon, 12 Oct 2026 14:36:24 +0000 X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: cch@e-psn.eu Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Thanks for catching this. On the B70 I observed two distinct symptoms after a sustained workload: - package/VRAM temperature values could remain stale while the physical blower stayed elevated even after the device had returned to idle; - fan1_input could independently report implausibly low or zero RPM while the physical blower was still running fast. This patch only addresses the temperature MMIO path. Holding XE_FW_GT for a short settling interval before the temperature read causes the temperature telemetry to refresh and, in my testing, the physical blower then settles normally as well. The REG_FAN_SPEED path remains a separate direct MMIO read and can still show unreliable values, so the current patch should not be read as fixing fan RPM telemetry itself. I can reword the commit message in a v2 to make that distinction explicit, and investigate the fan telemetry path separately. On 2026-10-12 13:59, sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 1 potential > issue(s) to consider: > - [Medium] drm/xe: fan telemetry lacks Battlemage thermal force-wake > workaround > -- > > commit a9faaf30cbf789280ad52add1cf188270e8ccad9 > Author: Constantinos Chalkias > > drm/xe/hwmon: refresh Battlemage thermal telemetry under force-wake > > This commit works around stale thermal telemetry on Battlemage by > acquiring the GT force-wake domain and waiting 500-1000 us before > reading temperature registers. > >> drm/xe/hwmon: refresh Battlemage thermal telemetry under force-wake >> >> On Battlemage, thermal telemetry can remain stale after the GT returns >> to RC6 following sustained workloads. >> >> On an Intel Arc Pro B70, package and VRAM temperature telemetry may >> stop >> refreshing after a long inference workload. Fan telemetry can also >> become invalid while the physical blower remains elevated. > > [Severity: Medium] > The commit message states that fan telemetry can become invalid, but > the > patch only applies the force-wake and delay workaround to temperature > and > VRAM channels via xe_hwmon_temp_mmio_read(). > > Does xe_hwmon_fan_input_read() also need this workaround? Currently, it > continues to read REG_FAN_SPEED directly via xe_mmio_read32() without > acquiring force-wake or delaying: > > drivers/gpu/drm/xe/xe_hwmon.c:xe_hwmon_fan_input_read() { > ... > mutex_lock(&hwmon->hwmon_lock); > > reg_val = xe_mmio_read32(mmio, xe_hwmon_get_reg(hwmon, REG_FAN_SPEED, > channel)); > time_now = get_jiffies_64(); > ... > } > > Will fan telemetry still remain susceptible to staleness on Battlemage > without the workaround?