From 224476613c8499f00ce4de975dd65749c5ca498c Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Thu, 28 Aug 2025 09:55:26 +0300 Subject: [PATCH] wifi: iwlwifi: if scratch is ~0U, consider it a failure We want to see bits being set in the scratch register upon resume, but if all the bits are set, it means that we were kicked out of the PCI bus and that clearly doesn't mean we can assume the firmware is still alive after the suspend / resume cycle. Fixes: cb347bd29d0d ("wifi: iwlwifi: mvm: fix hibernation") Signed-off-by: Emmanuel Grumbach Signed-off-by: Miri Korenblit Link: https://patch.msgid.link/20250828095500.0f203e559242.I59eff718cb5fda575db41081a1a389f7af488717@changeid --- drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c index b7add05f7a85..46d8c1922292 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c @@ -1222,11 +1222,15 @@ static int _iwl_pci_resume(struct device *device, bool restore) * Note: MAC (bits 0:7) will be cleared upon suspend even with wowlan, * but not bits [15:8]. So if we have bits set in lower word, assume * the device is alive. + * Alternatively, if the scratch value is 0xFFFFFFFF, then we no longer + * have access to the device and consider it powered off. * For older devices, just try silently to grab the NIC. */ if (trans->mac_cfg->device_family >= IWL_DEVICE_FAMILY_BZ) { - if (!(iwl_read32(trans, CSR_FUNC_SCRATCH) & - CSR_FUNC_SCRATCH_POWER_OFF_MASK)) + u32 scratch = iwl_read32(trans, CSR_FUNC_SCRATCH); + + if (!(scratch & CSR_FUNC_SCRATCH_POWER_OFF_MASK) || + scratch == ~0U) device_was_powered_off = true; } else { /* -- 2.51.0