From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F18DD21255B; Sun, 26 Oct 2025 14:50:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761490228; cv=none; b=R1ZfRMwfJVoRl2yPvYtJGzcp1/FvBoKWn+bhnroUC8jKd8cJzn0nZnanbJVnMzu/TWmG2eimO8Qo07tGTbhcghh+pV9t5n+/20jof14xoiyTY4um/tohZMS8LtKSXGaLZeRhq6fA6TQ8IfOS0wsMS9NOH5DtIrv0i2EvwPtu1rc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761490228; c=relaxed/simple; bh=yvUYs4SLZPYGpHto3wjMTtbzd/25aLTBF4Ho2HzVyY4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=COA7zCPhmgmvptaRbyuTwsZP8fiMAOnwUGiYbvyIrGzwGfsujUwq4wcJcp3UF6d8CO9KriBxciJ8hWEJaPk6KoMTBs1hb+evjiTH19ANDCzXroUiUgNKqYzTFZKEZEskgJFb+UYQxW8h7WEzXJuU9JTgikHcK9TiN7Viwu+ATw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IkoJEIkM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IkoJEIkM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79AA8C4CEE7; Sun, 26 Oct 2025 14:50:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761490227; bh=yvUYs4SLZPYGpHto3wjMTtbzd/25aLTBF4Ho2HzVyY4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IkoJEIkMFX0SoPlOpjBienAr0mImZkXnkIiinNmAZSvLMrbDbcetcHYfRdsNW42qx xnz7sbc1h9ZaoZ5K+QBcI6owXCmpZKTRV3SvhCMUfAPcqrxd8TotSeyyGvYj5oBYYK K4kYabV9z785WIgrxQmX2s/EH1i4lkF77i6jwGCRhs1hZiTR2PjqHK5M2RGpj+9GQd +j3dgtsGpSKJCOlfj9tzF9yrNbJzdn/yaSqCgB01uazZ2aX1qb82cSQRnG4b0YRVko s9wUh0G14UPYt8XWJ2binXzVOJ+BingcchnZQHBpv15zqFHvrgRbC5nABGmIEHGZXz wRmQAFijGZkHw== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Matthias Schiffer , Alexander Stein , Kevin Hilman , Stephen Boyd , Sasha Levin , kristo@kernel.org, alexandre.f.demers@gmail.com, linux-omap@vger.kernel.org Subject: [PATCH AUTOSEL 6.17-5.15] clk: ti: am33xx: keep WKUP_DEBUGSS_CLKCTRL enabled Date: Sun, 26 Oct 2025 10:48:52 -0400 Message-ID: <20251026144958.26750-14-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251026144958.26750-1-sashal@kernel.org> References: <20251026144958.26750-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.17.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Matthias Schiffer [ Upstream commit 1e0d75258bd09323cb452655549e03975992b29e ] As described in AM335x Errata Advisory 1.0.42, WKUP_DEBUGSS_CLKCTRL can't be disabled - the clock module will just be stuck in transitioning state forever, resulting in the following warning message after the wait loop times out: l3-aon-clkctrl:0000:0: failed to disable Just add the clock to enable_init_clks, so no attempt is made to disable it. Signed-off-by: Matthias Schiffer Signed-off-by: Alexander Stein Acked-by: Kevin Hilman Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: YES: The change simply marks WKUP_DEBUGSS as an always-on clock so the driver no longer violates the AM335x erratum. - `drivers/clk/ti/clk-33xx.c:261` now lists `l3-aon-clkctrl:0000:0` in `enable_init_clks`, explicitly keeping WKUP_DEBUGSS enabled as mandated by Errata Advisory 1.0.42; without this, the init sequence still tries to gate the module and hits the hardware deadlock described in the advisory. - Today the disable path waits for the module to idle, times out, and prints `l3-aon-clkctrl:0000:0: failed to disable` (`drivers/clk/ti/clkctrl.c:194`), so every boot (and any later clk_disable_unused run) produces user-visible errors while leaving the clock stuck in “transitioning”; the patch stops that erroneous transition request entirely. - Effect scope is tiny: one entry in an SoC-specific static list, matching how other errata workarounds (e.g. `l3-clkctrl:00bc:0`) are handled; the hardware already refuses to power down the block, so forcing it on introduces no new behaviour or power regression. - No API or structural change, only affects AM33xx clock init, and it backports cleanly to older kernels using the same `omap2_clk_enable_init_clocks()` helper. Suggested follow-up once backported: boot an AM335x board with `clk_ignore_unused` removed to confirm the “failed to disable” warning is gone. drivers/clk/ti/clk-33xx.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/clk/ti/clk-33xx.c b/drivers/clk/ti/clk-33xx.c index 85c50ea39e6da..9269e6a0db6a4 100644 --- a/drivers/clk/ti/clk-33xx.c +++ b/drivers/clk/ti/clk-33xx.c @@ -258,6 +258,8 @@ static const char *enable_init_clks[] = { "dpll_ddr_m2_ck", "dpll_mpu_m2_ck", "l3_gclk", + /* WKUP_DEBUGSS_CLKCTRL - disable fails, AM335x Errata Advisory 1.0.42 */ + "l3-aon-clkctrl:0000:0", /* AM3_L3_L3_MAIN_CLKCTRL, needed during suspend */ "l3-clkctrl:00bc:0", "l4hs_gclk", -- 2.51.0