On Tue, Dec 29, 2020 at 09:43:48AM +0100, Loic Poulain wrote:
> In AER capable root complex, errors are reported to the host which
> can then act accordingly and perform PCI recovering procedure.
>
> This patch enables error reporting and implements error_detected,
> slot_reset and resume callbacks.
>
> Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
> Reviewed-by Hemant Kumar <hemantk@xxxxxxxxxxxxxx>
> ---
> drivers/bus/mhi/pci_generic.c | 50 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
> index 3297d95..9fe1e30 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -8,6 +8,7 @@
> * Copyright (C) 2020 Linaro Ltd <loic.poulain@xxxxxxxxxx>
> */
>
> +#include <linux/aer.h>
> #include <linux/delay.h>
> #include <linux/device.h>
> #include <linux/mhi.h>
> @@ -405,6 +406,8 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> pci_save_state(pdev);
> mhi_pdev->pci_state = pci_store_saved_state(pdev);
>
> + pci_enable_pcie_error_reporting(pdev);
> +
> err = mhi_register_controller(mhi_cntrl, mhi_cntrl_config);
> if (err)
> return err;
> @@ -501,7 +504,54 @@ static void mhi_pci_reset_done(struct pci_dev *pdev)
> set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
> }
>
> +static pci_ers_result_t mhi_pci_error_detected(struct pci_dev *pdev,
> + pci_channel_state_t state)
> +{
> + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
> + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
> +
> + dev_err(&pdev->dev, "PCI error detected, state = %u\n", state);
> +
> + if (state == pci_channel_io_perm_failure)
> + return PCI_ERS_RESULT_DISCONNECT;
> +
> + /* Clean up MHI state */
> + if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
> + mhi_power_down(mhi_cntrl, false);
> + mhi_unprepare_after_power_down(mhi_cntrl);
> + } else {
> + /* Nothing to do */
> + return PCI_ERS_RESULT_RECOVERED;
> + }
> +
> + pci_disable_device(pdev);
> +
> + return PCI_ERS_RESULT_NEED_RESET;
> +}
> +
> +static pci_ers_result_t mhi_pci_slot_reset(struct pci_dev *pdev)
> +{
> + if (pci_enable_device(pdev)) {
> + dev_err(&pdev->dev, "Cannot re-enable PCI device after reset.\n");
> + return PCI_ERS_RESULT_DISCONNECT;
> + }
> +
This callback will be called after PCI slot reset, so we should also be resetting
the device after enabling it.
Thanks,
Mani
> + return PCI_ERS_RESULT_RECOVERED;
> +}
> +
> +static void mhi_pci_io_resume(struct pci_dev *pdev)
> +{
> + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
> +
> + dev_err(&pdev->dev, "PCI slot reset done\n");
> +
> + queue_work(system_long_wq, &mhi_pdev->recovery_work);
> +}
> +
> static const struct pci_error_handlers mhi_pci_err_handler = {
> + .error_detected = mhi_pci_error_detected,
> + .slot_reset = mhi_pci_slot_reset,
> + .resume = mhi_pci_io_resume,
> .reset_prepare = mhi_pci_reset_prepare,
> .reset_done = mhi_pci_reset_done,
> };
> --
> 2.7.4
>
