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

From: Sean V Kelley
Date: Thu Oct 01 2020 - 17:04:54 EST


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

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

From: Sean V Kelley <sean.v.kelley@xxxxxxxxx>

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 <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>

Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

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);