From: Ilpo Järvinen Date: Fri, 21 Mar 2025 16:31:03 +0000 (+0200) Subject: PCI/bwctrl: Fix pcie_bwctrl_select_speed() return type X-Git-Tag: v6.15-rc1~119^2~30^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=026e4bffb0af9632f5a0bbf8d594f2aace44cf07;p=thirdparty%2Fkernel%2Flinux.git PCI/bwctrl: Fix pcie_bwctrl_select_speed() return type pcie_bwctrl_select_speed() should take __fls() of the speed bit, not return it as a raw value. Instead of directly returning 2.5GT/s speed bit, simply assign the fallback speed (2.5GT/s) into supported_speeds variable to share the normal return path that calls pcie_supported_speeds2target_speed() to calculate __fls(). This code path is not very likely to execute because pcie_get_supported_speeds() should provide valid ->supported_speeds but a spec violating device could fail to synthesize any speed in pcie_get_supported_speeds(). It could also happen in case the supported_speeds intersection is empty (also a violation of the current PCIe specs). Link: https://lore.kernel.org/r/20250321163103.5145-1-ilpo.jarvinen@linux.intel.com Fixes: de9a6c8d5dbf ("PCI/bwctrl: Add pcie_set_target_speed() to set PCIe Link Speed") Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas --- diff --git a/drivers/pci/pcie/bwctrl.c b/drivers/pci/pcie/bwctrl.c index 0a5e7efbce2cc..58ba8142c9a31 100644 --- a/drivers/pci/pcie/bwctrl.c +++ b/drivers/pci/pcie/bwctrl.c @@ -113,7 +113,7 @@ static u16 pcie_bwctrl_select_speed(struct pci_dev *port, enum pci_bus_speed spe up_read(&pci_bus_sem); } if (!supported_speeds) - return PCI_EXP_LNKCAP2_SLS_2_5GB; + supported_speeds = PCI_EXP_LNKCAP2_SLS_2_5GB; return pcie_supported_speeds2target_speed(supported_speeds & desired_speeds); }