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 8A32037F730; Wed, 14 Jan 2026 09:36:54 +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=1768383414; cv=none; b=lIE+XuPLNpcmTG9GCXpEanrfszToaqnGLeRi5QD3U/LTmslgY+dcX+bv0/vB/mzZgldlc9noWOB0MdKxSZ20dz+GtcrKCRE5TeWNmRu83byr6XNutBiBoynPGFxqC55rLJa2uNFMy22jt//tSopu25q+fpLSGmQXEBcoRrqoNoI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768383414; c=relaxed/simple; bh=Vd4jldM+sSvbw3Qs+faOiMfuX6C/rjZRaR+/l4tHfHU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gpMUPKhkuiGjWJcnLsTsXrEN74u7wo2td6osAMP3CWstxor04JIwYoa9GzIhAJ4UNBLzOS8pDUlq5sP953lq4QlVzk28xVuVmGPQsmR6D34ksM0J1XVKrVvDEc8+tLJFAI0A/fFpb7l8rPxXeAg/MGsTKlw8QtCN/PAJ8kR4zNs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HqVOfbC4; 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="HqVOfbC4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58DFBC4CEF7; Wed, 14 Jan 2026 09:36:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768383414; bh=Vd4jldM+sSvbw3Qs+faOiMfuX6C/rjZRaR+/l4tHfHU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HqVOfbC46Uz/3VEhEysg9Z6Qh0ocLgMei+0QndPuf8J/aQ9JqBmm9xT/ObY/0gZ+J rpF7MptLiTMCDmZPQFbSr5OKMStMdawjfhkvvmNRiAVu6JDC91t8ZdmzF6oyj1xZu8 ePty8JFMbbXjazbIT07+odyE589qUa6oUyebKw6pM+hayhXEpOLMyR6OCrLm6tjTGz i39lkXMN0HW1hfWh8a12fbgf8/uKF9xv6FaT9PJJywNk3fTaQiTAUJkXd/6WDEc5Gq 7Wm5XwOjqcZjalGUZbWO/oLf527NMvtypUQ9sc05+fBwUie3VJ2Q1j7Ll9n3pIccLh eHBr6YS47PnbQ== Date: Wed, 14 Jan 2026 15:06:50 +0530 From: Vinod Koul To: Dmitry Baryshkov Cc: Neil Armstrong , Krishna Chaitanya Chundru , Philipp Zabel , Jingoo Han , Manivannan Sadhasivam , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH 1/5] phy: qcom: qmp-pcie: Skip PHY reset if already up Message-ID: References: <20260109-link_retain-v1-0-7e6782230f4b@oss.qualcomm.com> <20260109-link_retain-v1-1-7e6782230f4b@oss.qualcomm.com> <53f0c45f-7f5c-4abd-af84-cbb82d509872@linaro.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: On 09-01-26, 16:03, Dmitry Baryshkov wrote: > On Fri, Jan 09, 2026 at 02:10:49PM +0100, Neil Armstrong wrote: > > On 1/9/26 14:08, Dmitry Baryshkov wrote: > > > On Fri, Jan 09, 2026 at 12:51:06PM +0530, Krishna Chaitanya Chundru wrote: > > > > If the bootloader has already powered up the PCIe PHY, doing a full > > > > reset and waiting for it to come up again slows down boot time. > > > > > > How big is the delay caused by it? > > > > > > > > > > > Add a check for PHY status and skip the reset steps when the PHY is > > > > already active. In this case, only enable the required resources during > > > > power-on. This works alongside the existing logic that skips the init > > > > sequence. > > > > > > Can we end up in a state where the bootloader has mis-setup the link? Or > > > the link going bad because of any glitch during the bootup? > > > > Good question, can we add a module parameter to force a full reset of the PHY in case > > the bootloader is buggy ? > > I'd suggest a simpler thing: if the reset was skipped, reset the PHY in > case of an error and retry. That's also one of the reasons why I asked > for skip_reset not to be the persistent value. That is a better suggestion. Helps skips if it is configured and way to recover if buggy -- ~Vinod