Date:   Mon, 13 Feb 2023 15:01:12 -0600
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     bhelgaas@google.com, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        steev@kali.org
Subject: Re: [PATCH] PCI: pciehp: Add Qualcomm quirk for Command Completed
 erratum
Message-ID: <20230213210112.GA2931136@bhelgaas>
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In-Reply-To: <20230213144922.89982-1-manivannan.sadhasivam@linaro.org>
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On Mon, Feb 13, 2023 at 08:19:22PM +0530, Manivannan Sadhasivam wrote:
> The Qualcomm PCI bridge device (Device ID 0x010e) found in chipsets such as
> SC8280XP used in Lenovo Thinkpad X13s, does not set the Command Completed
> bit unless writes to the Slot Command register change "Control" bits.
> 
> This results in timeouts like below during boot and resume from suspend:
> 
>     pcieport 0002:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2020 msec ago)
>     ...
>     pcieport 0002:00:00.0: pciehp: Timeout on hotplug command 0x13f1 (issued 107724 msec ago)
> 
> Add the device to the Command Completed quirk to mark commands "completed"
> immediately unless they change the "Control" bits.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Applied to pci/hotplug for v6.3, thanks!

> ---
> 
> Bjorn, during the review of a similar patch adding the quirk for device id
> 0x0110, you asked me whether we should mark all Qcom bridge devices as
> quirky like Intel bridges. I tried asking this question to Qualcomm but
> found no answer yet. So I just went with adding one more entry.
> 
>  drivers/pci/hotplug/pciehp_hpc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index 10e9670eea0b..f8c70115b691 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -1088,6 +1088,8 @@ static void quirk_cmd_compl(struct pci_dev *pdev)
>  }
>  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
>  			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
> +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x010e,
> +			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
>  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0110,
>  			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
>  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
> -- 
> 2.25.1
>