On Wed, 2017-01-18 at 23:39 +0200, Michael S. Tsirkin wrote: > No hardware seems to actually call link_reset, and > no driver implements it as more than a nop stub. > > This drops the mentions of the callback from everywhere. > It's dropped from the documentation as well, but > the doc really needs to be updated to reflect > reality better (e.g. on pcie slot reset is the link reset). > > This will be done in a later patch. > > Signed-off-by: Michael S. Tsirkin This is going to conflict with the two patches I have in my for-next branch related to this same thing (it drops the stubs from qib and hfi1).  It would be easiest if I just added this to my for-next and fixed up the conflicts prior to submission. > --- >  Documentation/PCI/pci-error-recovery.txt | 24 +++------------------- > -- >  drivers/infiniband/hw/hfi1/pcie.c        | 10 ---------- >  drivers/infiniband/hw/qib/qib_pcie.c     |  8 -------- >  drivers/media/pci/ngene/ngene-cards.c    |  7 ------- >  include/linux/pci.h                      |  3 --- >  5 files changed, 3 insertions(+), 49 deletions(-) > > diff --git a/Documentation/PCI/pci-error-recovery.txt > b/Documentation/PCI/pci-error-recovery.txt > index ac26869..da3b217 100644 > --- a/Documentation/PCI/pci-error-recovery.txt > +++ b/Documentation/PCI/pci-error-recovery.txt > @@ -78,7 +78,6 @@ struct pci_error_handlers >  { >   int (*error_detected)(struct pci_dev *dev, enum > pci_channel_state); >   int (*mmio_enabled)(struct pci_dev *dev); > - int (*link_reset)(struct pci_dev *dev); >   int (*slot_reset)(struct pci_dev *dev); >   void (*resume)(struct pci_dev *dev); >  }; > @@ -104,8 +103,7 @@ if it implements any, it must implement > error_detected(). If a callback >  is not implemented, the corresponding feature is considered > unsupported. >  For example, if mmio_enabled() and resume() aren't there, then it >  is assumed that the driver is not doing any direct recovery and > requires > -a slot reset. If link_reset() is not implemented, the card is > assumed to > -not care about link resets. Typically a driver will want to know > about > +a slot reset.  Typically a driver will want to know about >  a slot_reset(). >   >  The actual steps taken by a platform to recover from a PCI error > @@ -232,25 +230,9 @@ proceeds to STEP 4 (Slot Reset) >   >  STEP 3: Link Reset >  ------------------ > -The platform resets the link, and then calls the link_reset() > callback > -on all affected device drivers.  This is a PCI-Express specific > state > +The platform resets the link.  This is a PCI-Express specific step >  and is done whenever a non-fatal error has been detected that can be > -"solved" by resetting the link. This call informs the driver of the > -reset and the driver should check to see if the device appears to be > -in working condition. > - > -The driver is not supposed to restart normal driver I/O operations > -at this point.  It should limit itself to "probing" the device to > -check its recoverability status. If all is right, then the platform > -will call resume() once all drivers have ack'd link_reset(). > - > - Result codes: > - (identical to STEP 3 (MMIO Enabled) > - > -The platform then proceeds to either STEP 4 (Slot Reset) or STEP 5 > -(Resume Operations). > - > ->>> The current powerpc implementation does not implement this > callback. > +"solved" by resetting the link. >   >  STEP 4: Slot Reset >  ------------------ > diff --git a/drivers/infiniband/hw/hfi1/pcie.c > b/drivers/infiniband/hw/hfi1/pcie.c > index 4ac8f33..ebd941f 100644 > --- a/drivers/infiniband/hw/hfi1/pcie.c > +++ b/drivers/infiniband/hw/hfi1/pcie.c > @@ -598,15 +598,6 @@ pci_slot_reset(struct pci_dev *pdev) >   return PCI_ERS_RESULT_CAN_RECOVER; >  } >   > -static pci_ers_result_t > -pci_link_reset(struct pci_dev *pdev) > -{ > - struct hfi1_devdata *dd = pci_get_drvdata(pdev); > - > - dd_dev_info(dd, "HFI1 link_reset function called, > ignored\n"); > - return PCI_ERS_RESULT_CAN_RECOVER; > -} > - >  static void >  pci_resume(struct pci_dev *pdev) >  { > @@ -625,7 +616,6 @@ pci_resume(struct pci_dev *pdev) >  const struct pci_error_handlers hfi1_pci_err_handler = { >   .error_detected = pci_error_detected, >   .mmio_enabled = pci_mmio_enabled, > - .link_reset = pci_link_reset, >   .slot_reset = pci_slot_reset, >   .resume = pci_resume, >  }; > diff --git a/drivers/infiniband/hw/qib/qib_pcie.c > b/drivers/infiniband/hw/qib/qib_pcie.c > index 6abe1c6..c379b83 100644 > --- a/drivers/infiniband/hw/qib/qib_pcie.c > +++ b/drivers/infiniband/hw/qib/qib_pcie.c > @@ -682,13 +682,6 @@ qib_pci_slot_reset(struct pci_dev *pdev) >   return PCI_ERS_RESULT_CAN_RECOVER; >  } >   > -static pci_ers_result_t > -qib_pci_link_reset(struct pci_dev *pdev) > -{ > - qib_devinfo(pdev, "QIB link_reset function called, > ignored\n"); > - return PCI_ERS_RESULT_CAN_RECOVER; > -} > - >  static void >  qib_pci_resume(struct pci_dev *pdev) >  { > @@ -707,7 +700,6 @@ qib_pci_resume(struct pci_dev *pdev) >  const struct pci_error_handlers qib_pci_err_handler = { >   .error_detected = qib_pci_error_detected, >   .mmio_enabled = qib_pci_mmio_enabled, > - .link_reset = qib_pci_link_reset, >   .slot_reset = qib_pci_slot_reset, >   .resume = qib_pci_resume, >  }; > diff --git a/drivers/media/pci/ngene/ngene-cards.c > b/drivers/media/pci/ngene/ngene-cards.c > index 423e8c8..8438c1c 100644 > --- a/drivers/media/pci/ngene/ngene-cards.c > +++ b/drivers/media/pci/ngene/ngene-cards.c > @@ -781,12 +781,6 @@ static pci_ers_result_t > ngene_error_detected(struct pci_dev *dev, >   return PCI_ERS_RESULT_CAN_RECOVER; >  } >   > -static pci_ers_result_t ngene_link_reset(struct pci_dev *dev) > -{ > - printk(KERN_INFO DEVICE_NAME ": link reset\n"); > - return 0; > -} > - >  static pci_ers_result_t ngene_slot_reset(struct pci_dev *dev) >  { >   printk(KERN_INFO DEVICE_NAME ": slot reset\n"); > @@ -800,7 +794,6 @@ static void ngene_resume(struct pci_dev *dev) >   >  static const struct pci_error_handlers ngene_errors = { >   .error_detected = ngene_error_detected, > - .link_reset = ngene_link_reset, >   .slot_reset = ngene_slot_reset, >   .resume = ngene_resume, >  }; > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 30d6c16..316379c 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -661,9 +661,6 @@ struct pci_error_handlers { >   /* MMIO has been re-enabled, but not DMA */ >   pci_ers_result_t (*mmio_enabled)(struct pci_dev *dev); >   > - /* PCI Express link has been reset */ > - pci_ers_result_t (*link_reset)(struct pci_dev *dev); > - >   /* PCI slot has been reset */ >   pci_ers_result_t (*slot_reset)(struct pci_dev *dev); >   -- Doug Ledford     GPG KeyID: B826A3330E572FDD     Key fingerprint = AE6B 1BDA 122B 23B4 265B  1274 B826 A333 0E57 2FDD