From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail11.truemail.it (mail11.truemail.it [217.194.8.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4732D33C1B9; Thu, 4 Dec 2025 09:13:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.194.8.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764839628; cv=none; b=j6+/UHfl2pnMkbRIrsLcoR+bS40uKLP6JoJMQPM86wSeYdIIBEW3d6dp9Ehtov974nAcK1T6g/gQk6Kve+ePID7x16MxlMTpERJRLdIF5M8dHfVVY25vzMDglW2YGHVzYxDG3dKLW7miNK6wH1Dz5hQluaPoxaOHdvw18b7ceGU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764839628; c=relaxed/simple; bh=wfbSbaWyFFBGRDhQAIbjUUHVQuhqP/UeP0JJDwjJiWk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Br2CM/I4Aydo/OE1RssHidEaKfr5DKjWOm+OoFbRRPvcChpFhirwzyvsQd+kVpTCALH5wW9TxOclEbPfmGdyGn/NfZD5y/Yca8DWlIRBi6ta9+3oJ/6gYUgIPEUxULQQlyK8Qi4LqQBONmvddsXj907l730n+e7v0KshRBEYkxI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it; spf=pass smtp.mailfrom=dolcini.it; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b=b/1v/zaS; arc=none smtp.client-ip=217.194.8.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dolcini.it Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b="b/1v/zaS" Received: from gaggiata.pivistrello.it (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 920C21FB70; Thu, 4 Dec 2025 10:13:35 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dolcini.it; s=default; t=1764839615; bh=FCvm8NB2mjkwoFh/137wbYHLyhq16Db2hwU6duYeg6U=; h=Received:From:To:Subject; b=b/1v/zaSyY7KoLQLKkAH0+IJLeyvgCUfoQiQlRxcxtmE/CFrU2pN7kjdadk2oZL8G arjyIJvhCrchmb/3ON1ObO1ovvJWzbjH7ZAKPVNM84xNDUSOtI7uKRPeR820JaPfiK ij4j++PZRqHgwF/PCCvMaN87YhXPfyq7mXeTZFfr7ln+od18T+rFsUM6GTM33yFsWp OMSP881uRV8+f0iP4rE9+1LoAYgzUf0/4U/ecRkFf9BYl4hLIkA/fhk0j8bjN7QuTI vB5XGO5XPreTUWTFhjQ6yH8NuadknYvfn3F358Lf8QXW3JU3AjFPopJEDbPp0CiV/b hG6mBVOFB2gIQ== Received: by gaggiata.pivistrello.it (Postfix, from userid 1000) id 4C9507FA27; Thu, 4 Dec 2025 10:13:35 +0100 (CET) Date: Thu, 4 Dec 2025 10:13:35 +0100 From: Francesco Dolcini To: Mark Brown Cc: Francesco Dolcini , Siddharth Vadapalli , Anurag Dutta , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] spi: cadence-quadspi: Fix clock enable underflows due to runtime PM Message-ID: References: <20251202-spi-cadence-qspi-runtime-pm-imbalance-v1-1-aee8c7fa21f2@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251202-spi-cadence-qspi-runtime-pm-imbalance-v1-1-aee8c7fa21f2@kernel.org> Hello Mark, On Tue, Dec 02, 2025 at 10:53:44PM +0000, Mark Brown wrote: > The recent refactoring of where runtime PM is enabled done in commit > f1eb4e792bb1 ("spi: spi-cadence-quadspi: Enable pm runtime earlier to > avoid imbalance") made the fact that when we do a pm_runtime_disable() > in the error paths of probe() we can trigger a runtime disable which in > turn results in duplicate clock disables. Early on in the probe function > we do a pm_runtime_get_noresume() since the probe function leaves the > device in a powered up state but in the error path we can't assume that PM > is enabled so we also manually disable everything, including clocks. This > means that when runtime PM is active both it and the probe function release > the same reference to the main clock for the IP, triggering warnings from > the clock subsystem: > > [ 8.693719] clk:75:7 already disabled > [ 8.693791] WARNING: CPU: 1 PID: 185 at /usr/src/kernel/drivers/clk/clk.c:1188 clk_core_disable+0xa0/0xb > ... > [ 8.694261] clk_core_disable+0xa0/0xb4 (P) > [ 8.694272] clk_disable+0x38/0x60 > [ 8.694283] cqspi_probe+0x7c8/0xc5c [spi_cadence_quadspi] > [ 8.694309] platform_probe+0x5c/0xa4 > > Avoid this confused ownership by moving the pm_runtime_get_noresume() to > after the last point at which the probe() function can fail. > > Reported-by: Francesco Dolcini > Closes: https://lore.kernel.org/r/20251201072844.GA6785@francesco-nb > Signed-off-by: Mark Brown > Cc: stable@vger.kernel.org Unless I did some stupid mistake testing the patch, it does not fix the issue. Here the log with v6.18 + this patch [ 6.347380] ------------[ cut here ]------------ [ 6.352025] clk:75:7 already disabled [ 6.355727] WARNING: CPU: 2 PID: 180 at drivers/clk/clk.c:1188 clk_core_disable+0xa4/0xac [ 6.363921] Modules linked in: aes_ce_blk aes_ce_cipher ghash_ce gf128mul snd_soc_simple_card(+) snd_soc_simple_card_utils spi_cadence_quadspi(+) optee(+) display_connector tee tps65219_pwrbutton u sb_conn_gpio gpio_keys dwc3_am62 roles k3_j72xx_bandgap ti_ads1015 industrialio_triggered_buffer kfi fo_buf sa2ul hci_uart sha512 bluetooth rtc_ti_k3 ecdh_generic libsha512 sha256 ecc snd_soc_davinci_m casp snd_soc_ti_udma rfkill sha1 authenc snd_soc_ti_edma wave5 libaes snd_soc_ti_sdma cdns_dsi cdns_ dphy omap_hwspinlock lm75 omap_mailbox snd_soc_nau8822 i3c ina2xx lontium_lt8912b m_can_platform m_c an can_dev pwm_tiehrpwm spi_omap2_mcspi fuse ipv6 libsha1 autofs4 [ 6.421984] CPU: 2 UID: 0 PID: 180 Comm: (udev-worker) Not tainted 6.18.0+ #2 PREEMPT [ 6.429902] Hardware name: Toradex Verdin AM62P WB on Verdin Development Board (DT) [ 6.437555] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 6.444515] pc : clk_core_disable+0xa4/0xac [ 6.448708] lr : clk_core_disable+0xa4/0xac [ 6.452896] sp : ffff800080bd37f0 [ 6.456234] x29: ffff800080bd37f0 x28: 0000000000000000 x27: ffff000001924810 [ 6.463406] x26: ffff000001924810 x25: ffffd9bd273e0408 x24: ffff000001924800 [ 6.470554] x23: 0000000000000000 x22: ffff000001439800 x21: 00000000ffffffed [ 6.477693] x20: ffff000002476c00 x19: ffff000002476c00 x18: 0000000000000006 [ 6.484831] x17: 0000000000000000 x16: ffffd9bd3f665260 x15: 0720072007200720 [ 6.491970] x14: 0720072007200720 x13: 0720072007200720 x12: ffffd9bd401ee538 [ 6.499108] x11: 0000000000000058 x10: 0000000000000018 x9 : ffffd9bd401ee538 [ 6.506242] x8 : 0000000000000194 x7 : ffffd9bd40246538 x6 : ffffd9bd40246538 [ 6.513380] x5 : ffff00007fb886c8 x4 : 0000000000000000 x3 : 0000000000000027 [ 6.520518] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000005504300 [ 6.527656] Call trace: [ 6.530104] clk_core_disable+0xa4/0xac (P) [ 6.534296] clk_disable+0x30/0x4c [ 6.537706] cqspi_probe+0x7c0/0xc64 [spi_cadence_quadspi] [ 6.543209] platform_probe+0x5c/0xa4 [ 6.546885] really_probe+0xc0/0x39c [ 6.550467] __driver_probe_device+0x7c/0x14c [ 6.554831] driver_probe_device+0x3c/0x120 [ 6.559022] __driver_attach+0xc4/0x200 [ 6.559387] lt8912 1-0048: supply vccmipirx not found, using dummy regulator [ 6.562855] bus_for_each_dev+0x7c/0xdc [ 6.573734] driver_attach+0x24/0x30 [ 6.577315] bus_add_driver+0x110/0x240 [ 6.581158] driver_register+0x68/0x130 [ 6.585001] __platform_driver_register+0x24/0x30 [ 6.589714] cqspi_platform_driver_init+0x20/0x1000 [spi_cadence_quadspi] [ 6.596516] do_one_initcall+0x60/0x1e0 [ 6.600363] do_init_module+0x54/0x23c [ 6.604126] load_module+0x1810/0x1f14 [ 6.607886] init_module_from_file+0x88/0xcc [ 6.612168] __arm64_sys_finit_module+0x264/0x358 [ 6.616883] invoke_syscall.constprop.0+0x50/0xe0 [ 6.619334] lt8912 1-0048: supply vccsysclk not found, using dummy regulator [ 6.621583] do_el0_svc+0xa8/0xe0 [ 6.631945] el0_svc+0x3c/0x148 [ 6.635095] el0t_64_sync_handler+0xa0/0xf0 [ 6.639285] el0t_64_sync+0x198/0x19c [ 6.642955] ---[ end trace 0000000000000000 ]--- [ 6.655277] ------------[ cut here ]------------ [ 6.659991] clk:75:7 already unprepared [ 6.667941] WARNING: CPU: 2 PID: 180 at drivers/clk/clk.c:1047 clk_core_unprepare+0xe4/0x104 [ 6.668689] lt8912 1-0048: supply vcclvdstx not found, using dummy regulator [ 6.676411] Modules linked in: spidev evdev(+) rng_core aes_ce_blk aes_ce_cipher ghash_ce gf128mu l snd_soc_simple_card snd_soc_simple_card_utils spi_cadence_quadspi(+) optee display_connector tee t ps65219_pwrbutton usb_conn_gpio gpio_keys dwc3_am62 roles k3_j72xx_bandgap ti_ads1015 industrialio_t riggered_buffer kfifo_buf sa2ul hci_uart sha512 bluetooth rtc_ti_k3 ecdh_generic libsha512 sha256 ec c snd_soc_davinci_mcasp snd_soc_ti_udma rfkill sha1 authenc snd_soc_ti_edma wave5 libaes snd_soc_ti_ sdma cdns_dsi cdns_dphy omap_hwspinlock lm75 omap_mailbox snd_soc_nau8822 i3c ina2xx lontium_lt8912b m_can_platform m_can can_dev pwm_tiehrpwm spi_omap2_mcspi fuse ipv6 libsha1 autofs4 [ 6.699332] lt8912 1-0048: supply vcchdmitx not found, using dummy regulator [ 6.743120] CPU: 2 UID: 0 PID: 180 Comm: (udev-worker) Tainted: G W 6.18.0+ #2 P REEMPT [ 6.743139] Tainted: [W]=WARN [ 6.743142] Hardware name: Toradex Verdin AM62P WB on Verdin Development Board (DT) [ 6.743147] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 6.743153] pc : clk_core_unprepare+0xe4/0x104 [ 6.743168] lr : clk_core_unprepare+0xe4/0x104 [ 6.743175] sp : ffff800080bd37f0 [ 6.743178] x29: ffff800080bd37f0 x28: 0000000000000000 x27: ffff000001924810 [ 6.796577] x26: ffff000001924810 x25: ffffd9bd273e0408 x24: ffff000001924800 [ 6.799311] lt8912 1-0048: supply vcclvdspll not found, using dummy regulator [ 6.803704] x23: 0000000000000000 x22: ffff000001439800 x21: 00000000ffffffed [ 6.803713] x20: 0000000000000000 x19: ffff000002476c00 x18: 0000000000000000 [ 6.803723] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 6.803731] x14: 000000000000008f x13: 00000000efe4b99a x12: 00009b471872c248 [ 6.803740] x11: 00000000000000c0 x10: 00000000000009e0 x9 : ffff800080bd3660 [ 6.803749] x8 : ffff000005504d40 x7 : 000000000000b67e x6 : 000000000000ba61 [ 6.803758] x5 : 0000000078b6e217 x4 : 0000000000000818 x3 : 0000000000800000 [ 6.803767] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000005504300 [ 6.803777] Call trace: [ 6.803781] clk_core_unprepare+0xe4/0x104 (P) [ 6.825908] lt8912 1-0048: supply vcchdmipll not found, using dummy regulator [ 6.832255] clk_unprepare+0x2c/0x44 [ 6.832266] cqspi_probe+0x7c8/0xc64 [spi_cadence_quadspi] [ 6.832286] platform_probe+0x5c/0xa4 [ 6.894596] really_probe+0xc0/0x39c [ 6.898176] __driver_probe_device+0x7c/0x14c [ 6.902534] driver_probe_device+0x3c/0x120 [ 6.906715] __driver_attach+0xc4/0x200 [ 6.910548] bus_for_each_dev+0x7c/0xdc [ 6.914380] driver_attach+0x24/0x30 [ 6.917954] bus_add_driver+0x110/0x240 [ 6.921789] driver_register+0x68/0x130 [ 6.925627] __platform_driver_register+0x24/0x30 [ 6.930333] cqspi_platform_driver_init+0x20/0x1000 [spi_cadence_quadspi] [ 6.937128] do_one_initcall+0x60/0x1e0 [ 6.940968] do_init_module+0x54/0x23c [ 6.944720] load_module+0x1810/0x1f14 [ 6.948471] init_module_from_file+0x88/0xcc [ 6.952740] __arm64_sys_finit_module+0x264/0x358 [ 6.957445] invoke_syscall.constprop.0+0x50/0xe0 [ 6.962149] do_el0_svc+0xa8/0xe0 [ 6.965463] el0_svc+0x3c/0x148 [ 6.968605] el0t_64_sync_handler+0xa0/0xf0 [ 6.972785] el0t_64_sync+0x198/0x19c [ 6.976447] ---[ end trace 0000000000000000 ]---