On 25.03.2021 21:19, Bjorn Helgaas wrote:
> On Thu, Mar 25, 2021 at 10:24:28AM +0100, Marek Szyprowski wrote:
>> On 25.01.2021 05:48, Zhiqiang Hou wrote:
>>> From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
>>>
>>> In the dw_pcie_ep_init(), it depends on the detected iATU region
>>> numbers to allocate the in/outbound window management bit map.
>>> It fails after the commit 281f1f99cf3a ("PCI: dwc: Detect number
>>> of iATU windows").
>>>
>>> So this patch move the iATU region detection into a new function,
>>> move forward the detection to the very beginning of functions
>>> dw_pcie_host_init() and dw_pcie_ep_init(). And also remove it
>>> from the dw_pcie_setup(), since it's more like a software
>>> perspective initialization step than hardware setup.
>>>
>>> Fixes: 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows")
>>> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
>> This patch causes exynos-pcie to hang during the initialization. It
>> looks that some resources are not enabled yet, so calling
>> dw_pcie_iatu_detect() much earlier causes a hang. When I have some time,
>> I will try to identify what is needed to call it properly.
> Thanks, I dropped it for now. We can add it back after we figure out
> what the exynos issue is.
Thanks, I will try to identify at which point of initialization it is
safe to call iATU region detection.
> For reference, here's the patch I dropped (I had made some minor
> corrections to the commit log):
>
> commit fd4162f05194 ("PCI: dwc: Move iATU detection earlier")
> Author: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> Date: Mon Jan 25 12:48:03 2021 +0800
>
> PCI: dwc: Move iATU detection earlier
>
> dw_pcie_ep_init() depends on the detected iATU region numbers to allocate
> the in/outbound window management bitmap. It fails after 281f1f99cf3a
> ("PCI: dwc: Detect number of iATU windows").
>
> Move the iATU region detection into a new function, move the detection to
> the very beginning of dw_pcie_host_init() and dw_pcie_ep_init(). Also
> remove it from the dw_pcie_setup(), since it's more like a software
> initialization step than hardware setup.
>
> Fixes: 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows")
> Link: https://lore.kernel.org/r/20210125044803.4310-1-Zhiqiang.Hou@xxxxxxx
> Tested-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v5.11+
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 1c25d8337151..8d028a88b375 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -705,6 +705,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> }
> }
>
> + dw_pcie_iatu_detect(pci);
> +
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
> if (!res)
> return -EINVAL;
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 7e55b2b66182..52f6887179cd 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -319,6 +319,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
> return PTR_ERR(pci->dbi_base);
> }
>
> + dw_pcie_iatu_detect(pci);
> +
> bridge = devm_pci_alloc_host_bridge(dev, 0);
> if (!bridge)
> return -ENOMEM;
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 004cb860e266..a945f0c0e73d 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -660,11 +660,9 @@ static void dw_pcie_iatu_detect_regions(struct dw_pcie *pci)
> pci->num_ob_windows = ob;
> }
>
> -void dw_pcie_setup(struct dw_pcie *pci)
> +void dw_pcie_iatu_detect(struct dw_pcie *pci)
> {
> - u32 val;
> struct device *dev = pci->dev;
> - struct device_node *np = dev->of_node;
> struct platform_device *pdev = to_platform_device(dev);
>
> if (pci->version >= 0x480A || (!pci->version &&
> @@ -693,6 +691,13 @@ void dw_pcie_setup(struct dw_pcie *pci)
>
> dev_info(pci->dev, "Detected iATU regions: %u outbound, %u inbound",
> pci->num_ob_windows, pci->num_ib_windows);
> +}
> +
> +void dw_pcie_setup(struct dw_pcie *pci)
> +{
> + u32 val;
> + struct device *dev = pci->dev;
> + struct device_node *np = dev->of_node;
>
> if (pci->link_gen > 0)
> dw_pcie_link_set_max_speed(pci, pci->link_gen);
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 7247c8b01f04..7d6e9b7576be 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -306,6 +306,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> void dw_pcie_disable_atu(struct dw_pcie *pci, int index,
> enum dw_pcie_region_type type);
> void dw_pcie_setup(struct dw_pcie *pci);
> +void dw_pcie_iatu_detect(struct dw_pcie *pci);
>
> static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val)
> {
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
