From af9d34abf54a196d7aac88d87bd2925727889bb1 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 13 Sep 2023 14:56:38 +0300 Subject: [PATCH] wifi: iwlwifi: pcie: give up mem read if HW is dead If the hardware is not responding, as indicated by (currently) five consecutive HW errors during reading, then just give up and fail, rather than attempting forever and forever for this to not return any useful data anyway. Even though we no longer completely deadlock the machine if it takes a long time, we still make it pretty much unusable since we'll eventually hold the RTNL while waiting for this process to finish. Signed-off-by: Johannes Berg Signed-off-by: Gregory Greenman Link: https://lore.kernel.org/r/20230913145231.345af79f431c.I5ecde6b76b1e3a1572bd59d3cf8f827e767cedeb@changeid Signed-off-by: Johannes Berg --- drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index 51012435e39b5..93e10d7d12fb5 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -2288,6 +2288,8 @@ out: static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr, void *buf, int dwords) { +#define IWL_MAX_HW_ERRS 5 + unsigned int num_consec_hw_errors = 0; int offs = 0; u32 *vals = buf; @@ -2303,6 +2305,17 @@ static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr, while (offs < dwords) { vals[offs] = iwl_read32(trans, HBUS_TARG_MEM_RDAT); + + if (iwl_trans_is_hw_error_value(vals[offs])) + num_consec_hw_errors++; + else + num_consec_hw_errors = 0; + + if (num_consec_hw_errors >= IWL_MAX_HW_ERRS) { + iwl_trans_release_nic_access(trans); + return -EIO; + } + offs++; if (time_after(jiffies, end)) { -- 2.30.2