| Message ID | 1609231431-10048-8-git-send-email-loic.poulain@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | mhi: pci_generic: Misc improvements | expand |
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@linaro.org> > Reviewed-by Hemant Kumar <hemantk@codeaurora.org> > --- > 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@linaro.org> > */ > > +#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 >
Hi Mani, On Thu, 31 Dec 2020 at 08:18, Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote: > > 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@linaro.org> > > Reviewed-by Hemant Kumar <hemantk@codeaurora.org> > > --- > > drivers/bus/mhi/pci_generic.c | 50 +++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 50 insertions(+) > > +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. Yes, but that is done in mhi_pci_io_resume. From the PCI error recovery documentation, "drivers should not restart normal I/O processing operations at this point (in slot_reset) If all device drivers report success on this callback, the platform will call resume() to complete the sequence, and let the driver restart normal I/O processing." The actual MHI PCI/recovery is then done in resume (mhi_pci_io_resume). Regards, Loic
On Thu, Dec 31, 2020 at 10:27:01AM +0100, Loic Poulain wrote: > Hi Mani, > > On Thu, 31 Dec 2020 at 08:18, Manivannan Sadhasivam > <manivannan.sadhasivam@linaro.org> wrote: > > > > 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@linaro.org> > > > Reviewed-by Hemant Kumar <hemantk@codeaurora.org> > > > --- > > > drivers/bus/mhi/pci_generic.c | 50 +++++++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 50 insertions(+) > > > > +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. > > Yes, but that is done in mhi_pci_io_resume. > > From the PCI error recovery documentation, "drivers should not restart > normal I/O processing operations at this point (in slot_reset) If all > device drivers report success on this callback, the platform will call > resume() to complete the sequence, and let the driver restart normal > I/O processing." > The actual MHI PCI/recovery is then done in resume (mhi_pci_io_resume). > If you read one paragraph above, "This call gives drivers the chance to re-initialize the hardware (re-download firmware, etc.). At this point, the driver may assume that the card is in a fresh state and is fully functional. The slot is unfrozen and the driver has full access to PCI config space, memory mapped I/O space and DMA." So at the end of this call, the device is assumed to be functional (then only PCI_ERS_RESULT_RECOVERED makes sense). IMO, you should call mhi_pci_reset_prepare() in this callback and mhi_pci_reset_done() in resume(). No need to schedule the recovery work. Thanks, Mani > Regards, > Loic
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@linaro.org> */ +#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; + } + + 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, };
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@linaro.org> Reviewed-by Hemant Kumar <hemantk@codeaurora.org> --- drivers/bus/mhi/pci_generic.c | 50 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) -- 2.7.4