On Thu, 14 Apr 2022 at 08:58, Andrew Scull ascull@google.com wrote:
On Thu, 14 Apr 2022 at 01:42, Bin Meng bmeng.cn@gmail.com wrote:
On Thu, Apr 14, 2022 at 12:30 AM Andrew Scull ascull@google.com wrote:
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 47cd074aa1..fd2203420c 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -67,6 +67,13 @@ config PCI_SRIOV if available on a PCI Physical Function device and probe for applicable drivers.
+config PCI_ENHANCED_ALLOCATION
bool "Enable support for Enhanced Allocation of resources"default yhelpEnable support for Enhanced Allocation which can be used by supporteddevices in place of traditional BARS for allocation of resources.Why do we need a config option for EA as it can be figured out in the run time?
I wanted to have the option to disable the logic for handling EA at runtime. A glance at the code suggested there's a whole other rabbit hole of missing safety checks that I've opted to leave for another day.
We cannot have a single global option to work for one device using EA but another device using BAR.
Sorry, I don't understand what you mean. This config will just mean the u-boot doesn't look for, or handle, the EA capability; it disables u-boot's support for this feature. If a system relies on EA, they'll need to have it enabled which is the default state. If a system doesn't then it can be turned off and the suspect logic disabled.
Could you help me understand your concern?
A neater version of the last hunk is below. But if you still don't think it belongs upstream, I'll remove it from the series to unblock the rest.
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c index 8bbeb62f2e..c4fe4e481a 100644 --- a/drivers/pci/pci-uclass.c +++ b/drivers/pci/pci-uclass.c @@ -645,7 +645,11 @@ int dm_pci_hose_probe_bus(struct udevice *bus) return log_msg_ret("probe", -EINVAL); }
- ea_pos = dm_pci_find_capability(bus, PCI_CAP_ID_EA); + if (IS_ENABLED(CONFIG_PCI_ENHANCED_ALLOCATION)) + ea_pos = dm_pci_find_capability(bus, PCI_CAP_ID_EA); + else + ea_pos = 0; + if (ea_pos) { dm_pci_read_config8(bus, ea_pos + sizeof(u32) + sizeof(u8), ®); @@ -1606,7 +1610,11 @@ void *dm_pci_map_bar(struct udevice *dev, int bar, unsigned long flags) * Incase of virtual functions, pdata will help read VF BEI * and EA entry size. */ - ea_off = dm_pci_find_capability(udev, PCI_CAP_ID_EA); + if (IS_ENABLED(CONFIG_PCI_ENHANCED_ALLOCATION)) + ea_off = dm_pci_find_capability(udev, PCI_CAP_ID_EA); + else + ea_off = 0; + if (ea_off) return dm_pci_map_ea_bar(udev, bar, ea_off, pdata);