Re: [PATCH v7 05/13] PCI/ERR: Use "bridge" for clarity in pcie_do_recovery()

[Sean V Kelley]

On 1 Oct 2020, at 2:06, Jonathan Cameron wrote:

On Wed, 30 Sep 2020 14:58:12 -0700
Sean V Kelley <seanvk....@oregontracks.org> wrote:

From: Sean V Kelley <sean.v.kel...@intel.com>

The term "dev" is being applied to root ports, switch
upstream ports, switch downstream ports, and the upstream
ports on endpoints. While endpoint upstream ports don't have
subordinate buses, a generic term such as "bridge" may be used

This sentence is a bit confusing.  The bit before the comma
seems only slightly connected. Perhaps 2 sentences?

I agree.  Will reword.

for something with a subordinate bus. The current conditional
logic in pcie_do_recovery() would also benefit from some
simplification with use of pci_upstream_bridge() in place of
dev->bus->self. Reverse the pcie_do_recovery() conditional logic
and replace use of "dev" with "bridge" for greater clarity.

Suggested-by: Bjorn Helgaas <bhelg...@google.com>
Signed-off-by: Sean V Kelley <sean.v.kel...@intel.com>

Acked-by: Jonathan Cameron <jonathan.came...@huawei.com>

Thanks,

Sean

---
 drivers/pci/pcie/err.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 950612342f1c..c6922c099c76 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c

@@ -152,16 +152,22 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,

 {
        pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
        struct pci_bus *bus;
+       struct pci_dev *bridge;
+       int type;

        /*

- * Error recovery runs on all subordinates of the first downstream port. - * If the downstream port detected the error, it is cleared at the end.

+        * Error recovery runs on all subordinates of the first downstream
+        * bridge. If the downstream bridge detected the error, it is
+        * cleared at the end.
         */
-       if (!(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
-             pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM))
-               dev = dev->bus->self;
-       bus = dev->subordinate;
-
+       type = pci_pcie_type(dev);
+       if (type == PCI_EXP_TYPE_ROOT_PORT ||
+           type == PCI_EXP_TYPE_DOWNSTREAM)
+               bridge = dev;
+       else
+               bridge = pci_upstream_bridge(dev);
+
+       bus = bridge->subordinate;
        pci_dbg(dev, "broadcast error_detected message\n");
        if (state == pci_channel_io_frozen) {
                pci_walk_bus(bus, report_frozen_detected, &status);