From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0913C606A330 for ; Fri, 13 Nov 2026 22:06:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=jNLXm+NR; dkim=pass (2048-bit key) header.d=kemnade.info header.i=@kemnade.info header.a=rsa-sha256 header.s=20220719 header.b=yw0/XLxK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; 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bh=vdmEB9hxIyAN0h7tY4BnByy/5E+TrrNwykX7GIFe6RY=; t=1794607611; x=1795817211; b=yw0/XLxK6g0LIH0wQI0KRy9KaPxvsyrw3QXtKFeV0VqymRW/+21RGk7CLTykYzgNcZI5wosMLW6 sndbZ0C54mDVeS1fokgfi2wUZ0H94GhN1LYeRrxsk0brmRY6MyH4rPkHtWwMcqp0i4+U4O4RHdpp4 9OLhBsVxSE3S8WhJ/2P5Gt45anhS5y9Rxx8R60bLmqMkZArknkv9dki5djYlE2kNMKWLDhOSvbsVi G0A9QEbdpb5UiPnELTVTr1h9TXpNzpOYPp66xCDd3WedLD0/tlrwW00dK215aRe5CD/kFLQa43/9x TKMxyEb7ehDh0we9+C2/BgBQeyxO891zYnDQ==; Date: Fri, 13 Nov 2026 23:06:44 +0100 From: Andreas Kemnade To: "Kevin Hilman (TI)" Cc: linux-omap@vger.kernel.org, Aaro Koskinen , Roger Quadros , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: OMAP2+: pm34xx: add NEON wakeup dependency before clockdomain idle Message-ID: <20261113230644.237c39ed@kemnade.info> In-Reply-To: <20261113-wip-omap3-vfp-neon-mismatch-v1-1-3f6f67b25251@baylibre.com> References: <20261113-wip-omap3-vfp-neon-mismatch-v1-1-3f6f67b25251@baylibre.com> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; aarch64-unknown-linux-gnu) X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261113_140652_077509_9F5A3F8F X-CRM114-Status: GOOD ( 22.57 ) X-Spam-Score: -2.1 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Fri, 13 Nov 2026 10:11:05 -0800 "Kevin Hilman (TI)" wrote: > On OMAP3630 (BeagleBoard-xM), about one boot in three dies early when > a context switch touches the VFP, which traps as undefined. > > The VFP is unreachable because NEON is powered off while the MPU runs. > omap3_pm_init() sets NEON's next state to OFF/RET and lets all > clockdomains idle before it adds the NEON -> MPU wakeup dependency, so > NEON can power down immediately and stay off until the MPU next idles. > This was visible in pm_debug, which showed neon_pwrdm OFF:1 while > mpu_pwrdm OFF:0. > > Add the wakeup dependency before the clockdomains are allowed to idle. > > Tested on omap3-beagle-xm: 6/17 boots crashed before, none of 25 after; > also ran 50 suspend/resume cycles each on omap3-beagle and -xm. > > Fixes: fa3c2a4fc99f ("OMAP3: PM: handle PER/NEON/CORE in idle") > Reported-by: Andreas Kemnade > Closes: https://lore.kernel.org/r/20261028212302.75ec622e@kemnade.info > Signed-off-by: Kevin Hilman (TI) survived a git bisect + several other boots on GTA04. (tested the identical change in a comment before) Tested-by: Andreas Kemnade # GTA04 > --- > This patch combined with an omap_device fix from Andreas makes OMAP3 > very stable on suspend/resume, including off-mode for OMAP3630. > c.f. https://lore.kernel.org/r/20261110211531.679943-1-andreas@kemnade.info > --- > arch/arm/mach-omap2/pm34xx.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c > index 9992549c7336..d11967c2f4bf 100644 > --- a/arch/arm/mach-omap2/pm34xx.c > +++ b/arch/arm/mach-omap2/pm34xx.c > @@ -510,6 +510,20 @@ int __init omap3_pm_init(void) > goto err3; > } > > + neon_clkdm = clkdm_lookup("neon_clkdm"); > + mpu_clkdm = clkdm_lookup("mpu_clkdm"); > + per_clkdm = clkdm_lookup("per_clkdm"); > + wkup_clkdm = clkdm_lookup("wkup_clkdm"); > + > + /* > + * Add the NEON wakeup dependency on the MPU before the clockdomains > + * are allowed to idle: once pwrdms_setup() has programmed NEON's next > + * state to OFF/RET, an idle NEON clockdomain otherwise lets NEON power > + * down while the MPU keeps running, and VFP instructions then trap as > + * undefined until NEON is woken. > + */ > + clkdm_add_wkdep(neon_clkdm, mpu_clkdm); > + > (void) clkdm_for_each(omap_pm_clkdms_setup, NULL); > > mpu_pwrdm = pwrdm_lookup("mpu_pwrdm"); > @@ -523,11 +537,6 @@ int __init omap3_pm_init(void) > per_pwrdm = pwrdm_lookup("per_pwrdm"); > core_pwrdm = pwrdm_lookup("core_pwrdm"); > > - neon_clkdm = clkdm_lookup("neon_clkdm"); > - mpu_clkdm = clkdm_lookup("mpu_clkdm"); > - per_clkdm = clkdm_lookup("per_clkdm"); > - wkup_clkdm = clkdm_lookup("wkup_clkdm"); > - > omap_common_suspend_init(omap3_pm_suspend); > > arm_pm_idle = omap3_pm_idle; > @@ -562,7 +571,6 @@ int __init omap3_pm_init(void) > if (IS_PM34XX_ERRATUM(PM_PER_MEMORIES_ERRATUM_i582)) > clkdm_add_wkdep(per_clkdm, wkup_clkdm); > > - clkdm_add_wkdep(neon_clkdm, mpu_clkdm); > if (omap_type() != OMAP2_DEVICE_TYPE_GP) { > omap3_secure_ram_storage = > kmalloc(OMAP3_SAVE_SECURE_RAM_SZ, GFP_KERNEL); > > --- > base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4 > change-id: 20261113-wip-omap3-vfp-neon-mismatch-ae585c1e8fe0 > > Best regards, > -- > Kevin Hilman (TI) > >