Ilpo Järvinen ilpo.jarvinen@linux.intel.com wrote:
Ever since introduction in the commit 0c8173385e54 ("rtl8192ce: Add new driver") the rtlwifi code has, according to comments, attempted to disable/enable ASPM of the upstream bridge by writing into its LNKCTL register. However, the code has never been correct because it performs the writes to the device instead of the upstream bridge.
Worse yet, the offset where the PCIe capabilities reside is derived from the offset of the upstream bridge. As a result, the write will use an offset on the device that does not relate to the LNKCTL register making the ASPM disable/enable code outright dangerous.
Because of those problems, there is no indication that the driver needs disable/enable ASPM on the upstream bridge. As the Capabilities offset is not correctly calculated for the write to target device's LNKCTL register, the code is not disabling/enabling device's ASPM either. Therefore, just remove the upstream bridge related ASPM disable/enable code entirely.
The upstream bridge related ASPM code was the only user of the struct mp_adapter members num4bytes, pcibridge_pciehdr_offset, and pcibridge_linkctrlreg so those are removed as well.
Note: This change does not remove the code related to changing the device's ASPM on purpose (which is independent of this flawed code related to upstream bridge's ASPM).
Suggested-by: Bjorn Helgaas bhelgaas@kernel.org Fixes: 0c8173385e54 ("rtl8192ce: Add new driver") Fixes: 886e14b65a8f ("rtlwifi: Eliminate raw reads and writes from PCIe portion") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
10 patches applied to wireless-next.git, thanks.
b3943b3c2971 wifi: rtlwifi: Remove bogus and dangerous ASPM disable/enable code 5894d0089cbc wifi: rtlwifi: Convert LNKCTL change to PCIe cap RMW accessors a4fcac11a25a wifi: rtlwifi: Convert to use PCIe capability accessors 6e071ae899f1 wifi: rtlwifi: rtl8821ae: Remove unnecessary PME_Status bit set 760bfed91201 wifi: rtlwifi: rtl8821ae: Reverse PM Capability exists check 9dcc75e0b7d0 wifi: rtlwifi: rtl8821ae: Use pci_find_capability() 7bd350d2ac91 wifi: rtlwifi: rtl8821ae: Add pdev into _rtl8821ae_clear_pci_pme_status() 05b311a3f915 wifi: rtlwifi: rtl8821ae: Access full PMCS reg and use pci_regs.h 217fbc032eaa wifi: rtlwifi: Remove unused PCI related defines and struct 874a0eda000d wifi: rtlwifi: Remove bridge vendor/device ids