From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 847364E8E15; Thu, 15 Oct 2026 13:51:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792072291; cv=none; b=mtxljQrfeLJcOu/AN6S+mopkuaJh72LR3claC8ke60kgEJCN3v0svr8x9h+ikhpbE9qeqnM79uGRwJtL8JT4Dq7P1TQxIw/QBOrSBg1EmNwTmUNJnYao5fk8wxfO/yrgJp84AL6aQwfIE8uQHKYYC6UieKC1gLIphKdM3MjeiFE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792072291; c=relaxed/simple; bh=RAY21xpGqEs8ofV/k20DKQeUzNm/8Inq5CJjVCWvefg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KLd1YIhkNuKTXKJmi9gobMlAOYiqRYn4qow2zlqzhNNIGwTE1yJBtyXAoFo2OhPrQzYGFMYHbvX+TvzMmU1tVbvY6ZO/YGiUoLrtUNJvelcuWIgSP5JdzOyakA+Pj2I6zFF8rNdU1kmNi0r/vZINRbbAsYoLz3eWkmwV+owWjuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zf1jItGk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Zf1jItGk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C65101F000C4; Thu, 15 Oct 2026 13:51:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792072290; bh=LQL9K7FjotLrNIQa5EP0wrOkT/xTAPGvJiGrgbZ57gs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Zf1jItGkxeDKvZwKtxSrdc+c2zH1+At/56XkmzrwOfJJvX6GXoRvtliRF2108ZLR6 VQGL/yPphm1XF1Mvd02TrlFvIPf8SrKh8nFNyt8iEuqFC738kcOx1WzfJgV2n+9mjz q8NFeTbU8FfMqFC0OxPN/ErWJqFYiWvS/7AuGFUp8cK6hrQKjXFkXZGx890/tbYaKH CmOpFkMAwhP5Swv2HUANQ0ZmjYhH9+ehdegW/Gl+s2QyYkGKRsTc4GRFzPrYpICzGa 9dVtqyHRxIp3AiPrYbZzv7p6Zske3u2Dm4r5k0wb1zr9bTby36jEu1VmQoyhno1AbZ fBk2gF5zHliIg== Date: Thu, 15 Oct 2026 19:21:10 +0530 From: Manivannan Sadhasivam To: Slark Xiao Cc: Krishna Chaitanya Chundru , jeff.hugo@oss.qualcomm.com, mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] bus: mhi: host: pci_generic: Add autosuspend_delay customized support Message-ID: References: <20260919095506.9570-1-slark_xiao@163.com> <1bec2fd7.99f3.1a0c8ea4db6.Coremail.slark_xiao@163.com> <2b0d3e13-96fa-437a-9de9-4a61911fe232@oss.qualcomm.com> <5506abc6.8919.1a11aab7e81.Coremail.slark_xiao@163.com> <6e90be7f.4d64.1a13e32174b.Coremail.slark_xiao@163.com> Precedence: bulk X-Mailing-List: mhi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6e90be7f.4d64.1a13e32174b.Coremail.slark_xiao@163.com> On Thu, Oct 15, 2026 at 02:13:52PM +0800, Slark Xiao wrote: > > At 2026-10-11 17:46:22, "Manivannan Sadhasivam" wrote: > >On Thu, Oct 08, 2026 at 04:40:09PM +0800, Slark Xiao wrote: > >> > >> > >> At 2026-09-26 19:26:15, "Manivannan Sadhasivam" wrote: > >> >On Wed, Sep 23, 2026 at 09:24:55AM +0530, Krishna Chaitanya Chundru wrote: > >> >> > >> >> > >> >> On 9/22/2026 5:09 PM, Slark Xiao wrote: > >> >> > At 2026-09-22 12:12:35, "Krishna Chaitanya Chundru" wrote: > >> >> >> > >> >> >> On 9/19/2026 3:25 PM, Slark Xiao wrote: > >> >> >>> For some WWAN device, it may get a SYS ERROR issue when resuming > >> >> >>> from suspend state frequently. Refer to the Qualcomm Windows > >> >> >>> driver, the default value of autosuspend_delay_ms is set as 5000 > >> >> >>> ms. But in Linux side, all WWAN device were set as 2000ms. We > >> >> >>> tried to set this value to 5000ms and we can get a positive test > >> >> >>> result. > >> >> >>> > >> >> >>> So we add a support to allow vendor to set a difference value for > >> >> >>> specific WWAN device. > >> >> >> you can change auto suspend delay from sysfs, please use that way instead of > >> >> >> doing in the driver. > >> >> >> > >> >> >> - Krishna Chaitanya. > >> >> > Yes, we can do this by setting the sysfs API . However, not all users > >> >> > are aware of this method. Additionally, this approach is only > >> >> > effective for a single instance; it requires reconfiguration after each > >> >> > restart, which is quite inconvenient. > >> >> you can have udev rule to set this without any user intervention. > >> > > >> >We should not rely on userspace to fix the SYS_ERROR. Userspace knob should only > >> >be exercised to customize the delay for power management purposes, not to fix > >> >firmware crash. > >> > >> > > >> Agree. We are still working on the issue debug on the modem side. > >> > >> >First we should know whether the default delay can be increased to 5000ms for > >> >all devices or not. If that is not desired, then we can go for Endpoint specific > >> >delay. > >> > > >> >- Mani > >> > > >> For reference, MTK 5G modem T700 is using 5000ms as default value. And Qualcomm > >> Windows drivers side, the default value is 5000ms as well. > >> However, I cannot guarantee that if all MHI devices are adjusted to 5000ms, some > >> power-sensitive devices will not oppose this change. Additional, DELL hopes that > >> we only modify the SDX72 device while keeping the 2000ms setting for the SDX62 > >> devices, as there are currently no similar issues with the SDX62 platform. > >> > > > >I think we should know the root cause of the crash before adding my fix. Right > >now, we only know that it is a firmware crash, but we don't know if the crash is > >due to MHI stack or PCI bus. If it is the MHI stack, then we can quirk the > >device in pci_generic driver. If it is a PCI bus issue, then we need to handle > >the quirk in pci/quirks.c. > > > >- Mani > We provided the crash dumps to Qualcomm for further analysis. Issue seems > come from firmware side. Finally, Qualcomm recommend us to update this > auto suspend delay value to 5s. Otherwise we may get a unexpected issue > for some specific scenario. > And currently our customer agreed that we set this value to 5s for all DW5934e > products. So I want to add this update based on our real requirement. > Sure, go ahead and respin this patch - Mani -- மணிவண்ணன் சதாசிவம்