From: Niklas Cassel <cassel@kernel.org>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: "Jingoo Han" <jingoohan1@gmail.com>,
"Gustavo Pimentel" <gustavo.pimentel@synopsys.com>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Rob Herring" <robh@kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Marek Vasut" <marek.vasut+renesas@gmail.com>,
"Yoshihiro Shimoda" <yoshihiro.shimoda.uh@renesas.com>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Jonathan Hunter" <jonathanh@nvidia.com>,
"Kishon Vijay Abraham I" <kishon@ti.com>,
"Vidya Sagar" <vidyas@nvidia.com>,
"Vignesh Raghavendra" <vigneshr@ti.com>,
"Richard Zhu" <hongxing.zhu@nxp.com>,
"Lucas Stach" <l.stach@pengutronix.de>,
"Shawn Guo" <shawnguo@kernel.org>,
"Sascha Hauer" <s.hauer@pengutronix.de>,
"Pengutronix Kernel Team" <kernel@pengutronix.de>,
"Fabio Estevam" <festevam@gmail.com>,
"NXP Linux Team" <linux-imx@nxp.com>,
"Minghuan Lian" <minghuan.Lian@nxp.com>,
"Mingkai Hu" <mingkai.hu@nxp.com>, "Roy Zang" <roy.zang@nxp.com>,
"Kunihiko Hayashi" <hayashi.kunihiko@socionext.com>,
"Masami Hiramatsu" <mhiramat@kernel.org>,
"Kishon Vijay Abraham I" <kishon@kernel.org>,
"Jesper Nilsson" <jesper.nilsson@axis.com>,
"Srikanth Thokala" <srikanth.thokala@intel.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-renesas-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-tegra@vger.kernel.org, linux-omap@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@axis.com,
"Frank Li" <Frank.Li@nxp.com>
Subject: Re: [PATCH v9 07/10] PCI: dwc: ep: Remove "core_init_notifier" flag
Date: Fri, 8 Mar 2024 14:24:35 +0100 [thread overview]
Message-ID: <ZesRk5Dg4KEASD3U@ryzen> (raw)
In-Reply-To: <20240304-pci-dbi-rework-v9-7-29d433d99cda@linaro.org>
On Mon, Mar 04, 2024 at 02:52:19PM +0530, Manivannan Sadhasivam wrote:
> "core_init_notifier" flag is set by the glue drivers requiring refclk from
> the host to complete the DWC core initialization. Also, those drivers will
> send a notification to the EPF drivers once the initialization is fully
> completed using the pci_epc_init_notify() API. Only then, the EPF drivers
> will start functioning.
>
> For the rest of the drivers generating refclk locally, EPF drivers will
> start functioning post binding with them. EPF drivers rely on the
> 'core_init_notifier' flag to differentiate between the drivers.
> Unfortunately, this creates two different flows for the EPF drivers.
>
> So to avoid that, let's get rid of the "core_init_notifier" flag and follow
> a single initialization flow for the EPF drivers. This is done by calling
> the dw_pcie_ep_init_notify() from all glue drivers after the completion of
> dw_pcie_ep_init_registers() API. This will allow all the glue drivers to
> send the notification to the EPF drivers once the initialization is fully
> completed.
>
> Only difference here is that, the drivers requiring refclk from host will
> send the notification once refclk is received, while others will send it
> during probe time itself.
>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 18c80002d3bd..fc0282b0d626 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -927,21 +928,12 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> if (ret)
> return ret;
>
Hello Mani,
Since you asked for testing, I gave your series a spin
(with a driver without .core_init_notifier).
There seems to be a problem that pci_epc_write_header() is never called.
Debugging this, it seems that .core_init in pci-epf-test is never called.
If I add debug prints in pci_epc_init_notify(), I see that it does not
notify a single EPF driver.
It appears that the patch in $subject will call pci_epc_init_notify()
at EPC driver .probe() time, and at that point in time, there are no
EPF drivers registered.
They get registered later, when doing the configfs write.
I would say that it is the following change that breaks things:
> - if (!core_init_notifier) {
> - ret = pci_epf_test_core_init(epf);
> - if (ret)
> - return ret;
> - }
> -
Since without this code, pci_epf_test_core_init() will no longer be called,
as there is currently no one that calls epf->core_init() for a EPF driver
after it has been bound. (For drivers that call dw_pcie_ep_init_notify() in
.probe())
I guess one way to solve this would be for the EPC core to keep track of
the current EPC "core state" (up/down). If the core is "up" at EPF .bind()
time, notify the EPF driver directly after .bind()?
Kind regards,
Niklas
next prev parent reply other threads:[~2024-03-08 13:24 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-04 9:22 [PATCH v9 00/10] PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host Manivannan Sadhasivam
2024-03-04 9:22 ` [PATCH v9 01/10] PCI: dwc: ep: Remove deinit() callback from struct dw_pcie_ep_ops Manivannan Sadhasivam
2024-03-07 19:52 ` Niklas Cassel
2024-03-08 11:17 ` Yoshihiro Shimoda
2024-03-04 9:22 ` [PATCH v9 02/10] PCI: dwc: ep: Rename dw_pcie_ep_exit() to dw_pcie_ep_deinit() Manivannan Sadhasivam
2024-03-07 19:52 ` Niklas Cassel
2024-03-08 11:18 ` Yoshihiro Shimoda
2024-03-04 9:22 ` [PATCH v9 03/10] PCI: dwc: ep: Introduce dw_pcie_ep_cleanup() API for drivers supporting PERST# Manivannan Sadhasivam
2024-03-07 20:14 ` Niklas Cassel
2024-03-04 9:22 ` [PATCH v9 04/10] PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host Manivannan Sadhasivam
2024-03-07 20:31 ` Niklas Cassel
2024-03-08 5:34 ` Manivannan Sadhasivam
2024-03-04 9:22 ` [PATCH v9 05/10] PCI: dwc: ep: Rename dw_pcie_ep_init_complete() to dw_pcie_ep_init_registers() Manivannan Sadhasivam
2024-03-07 20:32 ` Niklas Cassel
2024-03-04 9:22 ` [PATCH v9 06/10] PCI: dwc: ep: Call dw_pcie_ep_init_registers() API directly from all glue drivers Manivannan Sadhasivam
2024-03-07 20:36 ` Niklas Cassel
2024-03-08 5:36 ` Manivannan Sadhasivam
2024-03-08 9:05 ` Niklas Cassel
2024-03-08 9:49 ` Manivannan Sadhasivam
2024-03-08 10:22 ` Niklas Cassel
2024-03-14 7:22 ` Manivannan Sadhasivam
2024-03-08 11:22 ` Yoshihiro Shimoda
2024-03-04 9:22 ` [PATCH v9 07/10] PCI: dwc: ep: Remove "core_init_notifier" flag Manivannan Sadhasivam
2024-03-07 21:09 ` Niklas Cassel
2024-03-08 5:38 ` Manivannan Sadhasivam
2024-03-08 8:48 ` Niklas Cassel
2024-03-08 9:44 ` Manivannan Sadhasivam
2024-03-08 13:24 ` Niklas Cassel [this message]
2024-03-11 14:45 ` Manivannan Sadhasivam
2024-03-11 21:54 ` Niklas Cassel
2024-03-13 17:53 ` Manivannan Sadhasivam
2024-03-04 9:22 ` [PATCH v9 08/10] PCI: dwc: ep: Add a generic dw_pcie_ep_linkdown() API to handle LINK_DOWN event Manivannan Sadhasivam
2024-03-07 21:43 ` Niklas Cassel
2024-03-08 5:41 ` Manivannan Sadhasivam
2024-03-08 8:56 ` Niklas Cassel
2024-03-08 9:46 ` Manivannan Sadhasivam
2024-03-08 10:14 ` Niklas Cassel
2024-03-04 9:22 ` [PATCH v9 09/10] PCI: qcom-ep: Use the " Manivannan Sadhasivam
2024-03-07 21:43 ` Niklas Cassel
2024-03-04 9:22 ` [PATCH v9 10/10] PCI: dwc: ep: Add Kernel-doc comments for APIs Manivannan Sadhasivam
2024-03-07 21:58 ` Niklas Cassel
2024-03-08 5:43 ` Manivannan Sadhasivam
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