From: Niklas Cassel <cassel@kernel.org>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: "Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Rob Herring" <robh@kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Kishon Vijay Abraham I" <kishon@kernel.org>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Jonathan Hunter" <jonathanh@nvidia.com>,
"Jingoo Han" <jingoohan1@gmail.com>,
"Gustavo Pimentel" <gustavo.pimentel@synopsys.com>,
linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, mhi@lists.linux.dev,
linux-tegra@vger.kernel.org
Subject: Re: [PATCH 01/11] PCI: qcom-ep: Disable resources unconditionally during PERST# assert
Date: Fri, 22 Mar 2024 17:08:22 +0100 [thread overview]
Message-ID: <Zf2s9kTMlZncldWx@ryzen> (raw)
In-Reply-To: <20240314-pci-epf-rework-v1-1-6134e6c1d491@linaro.org>
On Thu, Mar 14, 2024 at 08:53:40PM +0530, Manivannan Sadhasivam wrote:
> All EP specific resources are enabled during PERST# deassert. As a counter
> operation, all resources should be disabled during PERST# assert. There is
> no point in skipping that if the link was not enabled.
>
> This will also result in enablement of the resources twice if PERST# got
> deasserted again. So remove the check from qcom_pcie_perst_assert() and
> disable all the resources unconditionally.
>
> Fixes: f55fee56a631 ("PCI: qcom-ep: Add Qualcomm PCIe Endpoint controller driver")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
> drivers/pci/controller/dwc/pcie-qcom-ep.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 2fb8c15e7a91..50b1635e3cbb 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -500,12 +500,6 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci)
> static void qcom_pcie_perst_assert(struct dw_pcie *pci)
> {
> struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> - struct device *dev = pci->dev;
> -
> - if (pcie_ep->link_status == QCOM_PCIE_EP_LINK_DISABLED) {
> - dev_dbg(dev, "Link is already disabled\n");
> - return;
> - }
>
> dw_pcie_ep_cleanup(&pci->ep);
> qcom_pcie_disable_resources(pcie_ep);
Are you really sure that this is safe?
I think I remember seeing some splat in dmesg if some clks, or maybe it
was regulators, got disabled while already being disabled.
Perhaps you could test it by simply calling:
qcom_pcie_disable_resources();
twice here, and see if you see and splat in dmesg.
Kind regards,
Niklas
next prev parent reply other threads:[~2024-03-22 16:08 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-14 15:23 [PATCH 00/11] PCI: endpoint: Make host reboot handling more robust Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 01/11] PCI: qcom-ep: Disable resources unconditionally during PERST# assert Manivannan Sadhasivam
2024-03-22 16:08 ` Niklas Cassel [this message]
2024-03-26 7:44 ` Manivannan Sadhasivam
2024-03-26 10:24 ` Niklas Cassel
2024-03-26 11:10 ` Manivannan Sadhasivam
2024-03-26 13:47 ` Niklas Cassel
2024-03-26 13:55 ` Manivannan Sadhasivam
2024-03-26 10:37 ` Niklas Cassel
2024-03-14 15:23 ` [PATCH 02/11] PCI: endpoint: Decouple EPC and PCIe bus specific events Manivannan Sadhasivam
2024-03-22 16:08 ` Niklas Cassel
2024-03-26 7:49 ` Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 03/11] PCI: endpoint: Rename core_init() callback in 'struct pci_epc_event_ops' to init() Manivannan Sadhasivam
2024-03-22 16:08 ` Niklas Cassel
2024-03-26 7:56 ` Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 04/11] PCI: epf-test: Refactor pci_epf_test_unbind() function Manivannan Sadhasivam
2024-03-22 16:09 ` Niklas Cassel
2024-03-26 7:58 ` Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 05/11] PCI: epf-{mhi/test}: Move DMA initialization to EPC init callback Manivannan Sadhasivam
2024-03-22 16:10 ` Niklas Cassel
2024-03-26 8:26 ` Manivannan Sadhasivam
2024-03-26 11:05 ` Niklas Cassel
2024-03-26 14:27 ` Niklas Cassel
2024-03-27 6:20 ` Manivannan Sadhasivam
2024-03-27 6:18 ` Manivannan Sadhasivam
2024-03-27 11:39 ` Niklas Cassel
2024-03-28 18:42 ` Vinod Koul
2024-04-04 8:44 ` Niklas Cassel
2024-04-22 7:55 ` Manivannan Sadhasivam
2024-04-22 9:30 ` Niklas Cassel
2024-03-14 15:23 ` [PATCH 06/11] PCI: endpoint: Introduce EPC 'deinit' event and notify the EPF drivers Manivannan Sadhasivam
2024-03-22 16:10 ` Niklas Cassel
2024-03-26 8:31 ` Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 07/11] PCI: dwc: ep: Add a generic dw_pcie_ep_linkdown() API to handle Link Down event Manivannan Sadhasivam
2024-03-22 16:10 ` Niklas Cassel
2024-03-27 18:06 ` Niklas Cassel
2024-04-01 16:34 ` Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 08/11] PCI: qcom-ep: Use the " Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 09/11] PCI: epf-test: Handle " Manivannan Sadhasivam
2024-03-22 16:10 ` Niklas Cassel
2024-03-14 15:23 ` [PATCH 10/11] PCI: qcom-ep: Rework {start/stop}_link() callbacks implementation Manivannan Sadhasivam
2024-03-22 16:10 ` Niklas Cassel
2024-03-26 8:33 ` Manivannan Sadhasivam
2024-03-14 15:23 ` [PATCH 11/11] PCI: tegra194: " Manivannan Sadhasivam
2024-03-22 16:11 ` Niklas Cassel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Zf2s9kTMlZncldWx@ryzen \
--to=cassel@kernel.org \
--cc=bhelgaas@google.com \
--cc=gustavo.pimentel@synopsys.com \
--cc=jingoohan1@gmail.com \
--cc=jonathanh@nvidia.com \
--cc=kishon@kernel.org \
--cc=kw@linux.com \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=lpieralisi@kernel.org \
--cc=manivannan.sadhasivam@linaro.org \
--cc=mhi@lists.linux.dev \
--cc=robh@kernel.org \
--cc=thierry.reding@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).