[+cc Andrew] On Thu, Aug 22, 2019 at 03:05:48PM -0500, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > Reads from a PCI device may fail if the device has been turned off (put > into D3cold), removed, or if some other error occurs. The PCI host bridge > typically fabricates ~0 data to complete the CPU's read. > > We check for that in a few places, but not in a consistent way. This > series adds a PCI_ERROR_RESPONSE definition to make the checks more > consistent and easier to find. Note that ~0 may indicate a PCI error, but > it may also be valid read data, so you need more information (such as > knowing that a register can never contain ~0) before concluding that it's > an error. > > This series also adds a new check for PCI_ERROR_RESPONSE in the power > management code because that code frequently encounters devices in D3cold, > where we previously misinterpreted ~0 data. It also uses pci_power_name() > to print D-state names more consistently. > > Rafael, I didn't add your Reviewed-by to "PCI / PM: Return error when > changing power state from D3cold" because I made small changes to try to > make the messages more consistent, and I didn't want to presume they'd be > OK with you. > > Changes since v1: > - Add Rafael's Reviewed-By to the first two patches > - Drop "PCI / PM: Check for error when reading PME status" because Rafael > pointed out that some devices can signal PME even when in D3cold, so > this would require additional rework > - Drop "PCI / PM: Check for error when reading Power State" because > Rafael thinks it's mostly redundant > > Bjorn Helgaas (3): > PCI: Add PCI_ERROR_RESPONSE definition > PCI / PM: Decode D3cold power state correctly > PCI / PM: Return error when changing power state from D3cold I applied patches 2 & 3 (tweaked to not depend on the PCI_ERROR_RESPONSE definition) with reviewed-by from Rafael, Keith, and Mika to pci/pm for v5.5, thanks everybody for taking a look. Andrew had good ideas for improving the PCI_ERROR_RESPONSE part, so it's gone for now but not forgotten. > drivers/pci/access.c | 13 ++++---- > .../pci/controller/dwc/pcie-designware-host.c | 2 +- > drivers/pci/controller/pci-aardvark.c | 2 +- > drivers/pci/controller/pci-mvebu.c | 4 +-- > drivers/pci/controller/pci-thunder-ecam.c | 20 ++++++------ > drivers/pci/controller/pci-thunder-pem.c | 2 +- > drivers/pci/controller/pcie-altera.c | 2 +- > drivers/pci/controller/pcie-iproc.c | 2 +- > drivers/pci/controller/pcie-mediatek.c | 4 +-- > drivers/pci/controller/pcie-rcar.c | 2 +- > drivers/pci/controller/pcie-rockchip-host.c | 2 +- > drivers/pci/controller/vmd.c | 2 +- > drivers/pci/hotplug/cpqphp_ctrl.c | 12 +++---- > drivers/pci/hotplug/cpqphp_pci.c | 20 ++++++------ > drivers/pci/hotplug/pciehp_hpc.c | 6 ++-- > drivers/pci/pci.c | 31 ++++++++++++------- > drivers/pci/pcie/dpc.c | 3 +- > drivers/pci/pcie/pme.c | 4 +-- > drivers/pci/probe.c | 4 +-- > drivers/pci/quirks.c | 2 +- > include/linux/pci.h | 7 +++++ > 21 files changed, 81 insertions(+), 65 deletions(-) > > -- > 2.23.0.187.g17f5b7556c-goog >
