From: Vidya Sagar <vidyas@nvidia.com>
To: Om Prakash Singh <omp@nvidia.com>, <kw@linux.com>,
<helgaas@kernel.org>, <lorenzo.pieralisi@arm.com>,
<bhelgaas@google.com>, <thierry.reding@gmail.com>,
<jonathanh@nvidia.com>
Cc: <linux-tegra@vger.kernel.org>, <linux-pci@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <kthota@nvidia.com>,
<mmaddireddy@nvidia.com>
Subject: Re: [PATCH V2 3/5] PCI: tegra: Disable interrupts before entering L2
Date: Tue, 8 Jun 2021 16:08:06 +0530 [thread overview]
Message-ID: <1c11a5c2-32be-85ec-cb0f-270cb5ad9576@nvidia.com> (raw)
In-Reply-To: <20210606082204.14222-4-omp@nvidia.com>
On 6/6/2021 1:52 PM, Om Prakash Singh wrote:
> In suspend_noirq() call if link doesn't goto L2, PERST# is asserted
> to bring link to detect state. However, this is causing surprise
> link down AER error. Since Kernel is executing noirq suspend calls,
> AER interrupt is not processed. PME and AER are shared interrupts
> and PCIe subsystem driver enables wake capability of PME irq during
> suspend. So this AER will cause suspend failure due to pending
> AER interrupt.
>
> After PCIe link is in L2, interrupts are not expected since PCIe
> controller will be in reset state. Disable PCIe interrupts before
> going to L2 state to avoid pending AER interrupt.
>
> Signed-off-by: Om Prakash Singh <omp@nvidia.com>
> ---
>
> Changes in V2:
> - Rephrase the commit message as per comment from Krzysztof Wilczyński
>
> drivers/pci/controller/dwc/pcie-tegra194.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 66e00b276cd3..64ec0da31b5b 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -1593,6 +1593,16 @@ static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
> return;
> }
>
> + /*
> + * PCIe controller exits from L2 only if reset is applied, so
> + * controller doesn't handle interrupts. But in cases where
> + * L2 entry fails, PERST# is asserted which can trigger surprise
> + * link down AER. However this function call happens in
> + * suspend_noirq(), so AER interrupt will not be processed.
> + * Disable all interrupts to avoid such a scenario.
> + */
> + appl_writel(pcie, 0x0, APPL_INTR_EN_L0_0);
> +
> if (tegra_pcie_try_link_l2(pcie)) {
> dev_info(pcie->dev, "Link didn't transition to L2 state\n");
> /*
>
Acked-by: Vidya Sagar <vidyas@nvidia.com>
next prev parent reply other threads:[~2021-06-08 10:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-06 8:21 [PATCH V2 0/5] Update pcie-tegra194 driver Om Prakash Singh
2021-06-06 8:22 ` [PATCH V2 1/5] PCI: tegra: Fix handling BME_CHGED event Om Prakash Singh
2021-06-08 10:37 ` Vidya Sagar
2021-06-06 8:22 ` [PATCH V2 2/5] PCI: tegra: Fix MSI-X programming Om Prakash Singh
2021-06-08 10:37 ` Vidya Sagar
2021-06-06 8:22 ` [PATCH V2 3/5] PCI: tegra: Disable interrupts before entering L2 Om Prakash Singh
2021-06-08 10:38 ` Vidya Sagar [this message]
2021-06-06 8:22 ` [PATCH V2 4/5] PCI: tegra: Don't allow suspend when Tegra PCIe is in EP mode Om Prakash Singh
2021-06-08 10:38 ` Vidya Sagar
2021-06-06 8:22 ` [PATCH V2 5/5] PCI: tegra: Cleanup unused code Om Prakash Singh
2021-06-08 10:38 ` Vidya Sagar
2021-06-21 9:32 ` [PATCH V2 0/5] Update pcie-tegra194 driver Om Prakash Singh
2021-06-21 18:30 ` Bjorn Helgaas
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