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 EF915199235; Mon, 7 Oct 2024 11:44:42 +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=1728301483; cv=none; b=QzwtzfPyIZ+LTt/6Pg1Xde8erCnLkYFmekTiupyAGN/SQ9ur0pZSCHx3/u1S2iwNf3r5ysLstl2y+JbjnNT7pzSgzpNwhfs17fRskRXjrdaaWUly0JHsRVSzoYHVzpm6FSvHkjuzNtAX99Cozn54sg8axf/L7uGa9OZFycOHKIo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728301483; c=relaxed/simple; bh=BdagRc9kDm8QW5L4yx71h6tv7jwW8Ojd8Q3cbF5c6CU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Gs31NWBukt6brdmIguYCBhObZgSQpMofGflXlt4J0TBYIPRjcfpAUjsf0GbJklWZmp75kvSVWcq4f7rbSCg7LVnXJTNrrTTfS3vytIWu88iSritNedfZXnqbSUqYSGv515+meTE/WVvIIOJf+CvTnvQ40J6QAiaFm0EuoYlHdEU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p4lTXEaF; 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="p4lTXEaF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D27D7C4CEC6; Mon, 7 Oct 2024 11:44:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728301482; bh=BdagRc9kDm8QW5L4yx71h6tv7jwW8Ojd8Q3cbF5c6CU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=p4lTXEaFcv2P0OnXd5GZOTtWQLLF+wfcvWE0on94SJrz+Sn2Yzoc05REKGvvsLA+2 U6jk9UL9xpE0OTLvMPvpOmMgOAHGGAwwo6GL4GqK8UlMOiSbZ1lxYomsaXLqiJCic0 rRUKVHX+ua1Fz1HIn7rryFLRP/+jnCJ7YfKrEMrl7OJQjJo/eLdG5pr5xjb4XFygur gk3o0GNq8o4aukr0tIt+k/nSrBF+dUOVtc/GHSwelRzSplndQgqnUyklBsH65EQSmm jIb1QJ0yg4HpclchjPUmDrXyD6rbf1vVIHX3Tnyh/fSvRGIufkvDHRLI4FhaBHGuM4 uWWLQVAcrZAxA== Message-ID: <5e6bb315-7896-4e63-86aa-1a219b7a7fb3@kernel.org> Date: Mon, 7 Oct 2024 14:44:35 +0300 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] usb: dwc3: core: Fix system suspend on TI AM62 platforms To: Thinh Nguyen Cc: "Rafael J. Wysocki" , Len Brown , Pavel Machek , Greg Kroah-Hartman , Nishanth Menon , Tero Kristo , Santosh Shilimkar , Dhruva Gole , Vishal Mahaveer , "msp@baylibre.com" , "srk@ti.com" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-usb@vger.kernel.org" , "stable@vger.kernel.org" References: <20241001-am62-lpm-usb-v1-1-9916b71165f7@kernel.org> <20241005010355.zyb54bbqjmpdjnce@synopsys.com> Content-Language: en-US From: Roger Quadros In-Reply-To: <20241005010355.zyb54bbqjmpdjnce@synopsys.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi, On 05/10/2024 04:04, Thinh Nguyen wrote: > Hi, > > On Tue, Oct 01, 2024, Roger Quadros wrote: >> Since commit 6d735722063a ("usb: dwc3: core: Prevent phy suspend during init"), >> system suspend is broken on AM62 TI platforms. >> >> Before that commit, both DWC3_GUSB3PIPECTL_SUSPHY and DWC3_GUSB2PHYCFG_SUSPHY >> bits (hence forth called 2 SUSPHY bits) were being set during core >> initialization and even during core re-initialization after a system >> suspend/resume. >> >> These bits are required to be set for system suspend/resume to work correctly >> on AM62 platforms. >> >> Since that commit, the 2 SUSPHY bits are not set for DEVICE/OTG mode if gadget >> driver is not loaded and started. >> For Host mode, the 2 SUSPHY bits are set before the first system suspend but >> get cleared at system resume during core re-init and are never set again. >> >> This patch resovles these two issues by ensuring the 2 SUSPHY bits are set >> before system suspend and restored to the original state during system resume. >> >> Cc: stable@vger.kernel.org # v6.9+ >> Fixes: 6d735722063a ("usb: dwc3: core: Prevent phy suspend during init") >> Link: https://urldefense.com/v3/__https://lore.kernel.org/all/1519dbe7-73b6-4afc-bfe3-23f4f75d772f@kernel.org/__;!!A4F2R9G_pg!ahChm4MaKd6VGYqbnM4X1_pY_jqavYDv5HvPFbmicKuhvFsBwlEFi1xO5itGuHmfjbRuUSzReJISf5-1gXpr$ >> Signed-off-by: Roger Quadros >> --- >> drivers/usb/dwc3/core.c | 16 ++++++++++++++++ >> drivers/usb/dwc3/core.h | 2 ++ >> 2 files changed, 18 insertions(+) >> >> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c >> index 9eb085f359ce..1233922d4d54 100644 >> --- a/drivers/usb/dwc3/core.c >> +++ b/drivers/usb/dwc3/core.c >> @@ -2336,6 +2336,9 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg) >> u32 reg; >> int i; >> >> + dwc->susphy_state = !!(dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) & >> + DWC3_GUSB2PHYCFG_SUSPHY); >> + >> switch (dwc->current_dr_role) { >> case DWC3_GCTL_PRTCAP_DEVICE: >> if (pm_runtime_suspended(dwc->dev)) >> @@ -2387,6 +2390,11 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg) >> break; >> } >> >> + if (!PMSG_IS_AUTO(msg)) { >> + if (!dwc->susphy_state) >> + dwc3_enable_susphy(dwc, true); >> + } >> + >> return 0; >> } >> >> @@ -2454,6 +2462,14 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg) >> break; >> } >> >> + if (!PMSG_IS_AUTO(msg)) { >> + /* dwc3_core_init_for_resume() disables SUSPHY so just handle >> + * the enable case >> + */ > > Can we note that this is a particular behavior needed for AM62 here? > And can we use this comment style: > > /* > * xxxxx > * xxxxx > */ OK. > > >> + if (dwc->susphy_state) > > Shouldn't we check for if (!dwc->susphy_state) and clear the susphy > bits? In that case it would have already been cleared so no need to check and clear again. > >> + dwc3_enable_susphy(dwc, true); > > The dwc3_enable_susphy() set and clear both GUSB3PIPECTL_SUSPHY and > GUSB2PHYCFG_SUSPHY, perhaps we should split that function out so we can > only need to set for GUSB2PHYCFG_SUSPHY since you only track for that. As dwc3_enable_susphy() sets and clears both GUSB3PIPECTL_SUSPHY and GUSB2PHYCFG_SUSPHY together it doesn't really help to track both separately, but just complicates things. > >> + } >> + >> return 0; >> } >> >> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h >> index c71240e8f7c7..b2ed5aba4c72 100644 >> --- a/drivers/usb/dwc3/core.h >> +++ b/drivers/usb/dwc3/core.h >> @@ -1150,6 +1150,7 @@ struct dwc3_scratchpad_array { >> * @sys_wakeup: set if the device may do system wakeup. >> * @wakeup_configured: set if the device is configured for remote wakeup. >> * @suspended: set to track suspend event due to U3/L2. >> + * @susphy_state: state of DWC3_GUSB2PHYCFG_SUSPHY before PM suspend. >> * @imod_interval: set the interrupt moderation interval in 250ns >> * increments or 0 to disable. >> * @max_cfg_eps: current max number of IN eps used across all USB configs. >> @@ -1382,6 +1383,7 @@ struct dwc3 { >> unsigned sys_wakeup:1; >> unsigned wakeup_configured:1; >> unsigned suspended:1; >> + unsigned susphy_state:1; >> >> u16 imod_interval; >> >> >> --- >> base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc >> change-id: 20240923-am62-lpm-usb-f420917bd707 >> >> Best regards, >> -- >> Roger Quadros >> > > > While reviewing your change, I see that we misuse the > dis_u2_susphy_quirk to make this property a conditional thing during > suspend and resume for certain platform. That bugs me because we can't > easily change it without the reported hardware to test. > No it is not conditional. if dis_u2_susphy_quirk or dis_u3_susphy_quirk is set then we never enable the respective U2/U3 SUSPHY bit. > > Thanks for the patch! > > BR, > Thinh -- cheers, -roger