On Fri, 11 Dec 2020 at 21:15, Hemant Kumar <hemantk@xxxxxxxxxxxxxx> wrote: > > > Hi Loic, > On 12/10/20 2:02 AM, Loic Poulain wrote: > > Add support for resetting the device, reset can be triggered in case > > of error or manually via sysfs (/sys/bus/pci/devices/*/reset). > > > > Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx> > > --- > > drivers/bus/mhi/pci_generic.c | 120 +++++++++++++++++++++++++++++++++++++----- > > 1 file changed, 107 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c > > index 077595c..d70d3ea 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/delay.h> > > #include <linux/device.h> > > #include <linux/mhi.h> > > #include <linux/module.h> > > @@ -177,6 +178,16 @@ static const struct pci_device_id mhi_pci_id_table[] = { > > }; > > MODULE_DEVICE_TABLE(pci, mhi_pci_id_table); > > > > +enum mhi_pci_device_status { > > + MHI_PCI_DEV_STARTED, > > +}; > > + > > +struct mhi_pci_device { > > + struct mhi_controller mhi_cntrl; > > + struct pci_saved_state *pci_state; > > + unsigned long status; > > +}; > > + > > static int mhi_pci_read_reg(struct mhi_controller *mhi_cntrl, > > void __iomem *addr, u32 *out) > > { > > @@ -196,6 +207,20 @@ static void mhi_pci_status_cb(struct mhi_controller *mhi_cntrl, > > /* Nothing to do for now */ > > } > > > > +static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl) > > +{ > > + struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev); > > + u16 vendor = 0; > > + > > + if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor)) > > + return false; > > + > > + if (vendor == (u16) ~0 || vendor == 0) > > + return false; > > + > > + return true; > > +} > > + > > static int mhi_pci_claim(struct mhi_controller *mhi_cntrl, > > unsigned int bar_num, u64 dma_mask) > > { > > @@ -291,16 +316,20 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > { > > const struct mhi_pci_dev_info *info = (struct mhi_pci_dev_info *) id->driver_data; > > const struct mhi_controller_config *mhi_cntrl_config; > > + struct mhi_pci_device *mhi_pdev; > > struct mhi_controller *mhi_cntrl; > > int err; > > > > dev_dbg(&pdev->dev, "MHI PCI device found: %s\n", info->name); > > > > - mhi_cntrl = mhi_alloc_controller(); > > - if (!mhi_cntrl) > > + mhi_pdev = devm_kzalloc(&pdev->dev, sizeof(*mhi_pdev), GFP_KERNEL); > > + if (!mhi_pdev) > > return -ENOMEM; > > > > mhi_cntrl_config = info->config; > > + mhi_cntrl = &mhi_pdev->mhi_cntrl; > > + > > + mhi_initialize_controller(mhi_cntrl); > > mhi_cntrl->cntrl_dev = &pdev->dev; > > mhi_cntrl->iova_start = 0; > > mhi_cntrl->iova_stop = DMA_BIT_MASK(info->dma_data_width); > > @@ -315,17 +344,21 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > > > err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width)); > > if (err) > > - goto err_release; > > + return err; > > > > err = mhi_pci_get_irqs(mhi_cntrl, mhi_cntrl_config); > > if (err) > > - goto err_release; > > + return err; > > + > > + pci_set_drvdata(pdev, mhi_pdev); > > > > - pci_set_drvdata(pdev, mhi_cntrl); > > + /* Have stored pci confspace at hand for restore in sudden PCI error */ > > + pci_save_state(pdev); > > + mhi_pdev->pci_state = pci_store_saved_state(pdev); > > > > err = mhi_register_controller(mhi_cntrl, mhi_cntrl_config); > > if (err) > > - goto err_release; > > + return err; > > > > /* MHI bus does not power up the controller by default */ > > err = mhi_prepare_for_power_up(mhi_cntrl); > > @@ -340,33 +373,94 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > goto err_unprepare; > > } > > > > + set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status); > > + > > return 0; > > > > err_unprepare: > > mhi_unprepare_after_power_down(mhi_cntrl); > > err_unregister: > > mhi_unregister_controller(mhi_cntrl); > > -err_release: > > - mhi_free_controller(mhi_cntrl); > > > > return err; > > } > > > > static void mhi_pci_remove(struct pci_dev *pdev) > > { > > - struct mhi_controller *mhi_cntrl = pci_get_drvdata(pdev); > > + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev); > > + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl; > > + > > + if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) { > > + mhi_power_down(mhi_cntrl, true); > > + mhi_unprepare_after_power_down(mhi_cntrl); > > + } > > > > - mhi_power_down(mhi_cntrl, true); > > - mhi_unprepare_after_power_down(mhi_cntrl); > > mhi_unregister_controller(mhi_cntrl); > > - mhi_free_controller(mhi_cntrl); > > } > > > > +void mhi_pci_reset_prepare(struct pci_dev *pdev) > any reason for not making it static ? > > +{ > > + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev); > > + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl; > > + > > + dev_info(&pdev->dev, "reset\n"); > > + > > + /* 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); > > + } > > + > > + /* cause internal device reset */ > > + mhi_reg_soc_reset(mhi_cntrl); > > + > > + /* Be sure device reset has been executed */ > > + msleep(500); > one suggestion, since you are adding this support for any generic MHI > controller, would it be good to make this configurable in case some > devcices need mode time to complete reset? I can add a define, but 500ms is more than enough to cause device reset, it's overkill to have a per controller value, in worst case we can increase the value. Regards, Loic