From d4626f91739b76633dbb3013e843e178c4a26618 Mon Sep 17 00:00:00 2001 From: Mordechay Goodstein Date: Tue, 30 Mar 2021 16:24:57 +0300 Subject: iwlwifi: pcie: clear only FH bits handle in the interrupt For simplicity we assume that msix has 2 IRQ lines one used for rx data called msix_non_share, and another used for one bit flags messages (alive, hw error, sw error, rx data flag) called msix_share. Every time the FW has data to send it puts it on the RX queue and HW turns on the flags in msix_share (inta_fw) indicating about rx data, and HW sends an interrupt a bit later to the msix_non_share _unless_ the msix_shared RX data bit was cleared. Currently in the code every time we get an msix_shared we clear all bits including rx data queue bits. So we can have a race ---------------------------------------------------- DRIVER | HW | FW ---------------------------------------------------- - send host cmd to FW | | | | - handle message | | and put a response | | on the RX queue | - RX flag on | | | - send alive msix | - alive flag on | | - interrupt | | msix_share driver | - handle msix_shared | | and clear all flags | | bits | | | - don't send an | | interrupt on | | msix_non_shared | | (driver cleared) | - driver timeout on | | waiting for host cmd | | respond | | | | ---------------------------------------------------- The change is to clear only the msi_shared flags that are handled in the msix_shared flow, which will cause the hardware to send an interrupt on the msix_non_share line as well, when it has data. Signed-off-by: Mordechay Goodstein Signed-off-by: Luca Coelho Link: https://lore.kernel.org/r/iwlwifi.20210330162204.a1cdda2fa270.I02a82312679f4541f30bb8db8747a797dbb70ee7@changeid Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/iwl-csr.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/net/wireless/intel/iwlwifi/iwl-csr.h') diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-csr.h b/drivers/net/wireless/intel/iwlwifi/iwl-csr.h index 6ccde7e30211..db312abd2e09 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-csr.h +++ b/drivers/net/wireless/intel/iwlwifi/iwl-csr.h @@ -578,6 +578,9 @@ enum msix_fh_int_causes { MSIX_FH_INT_CAUSES_FH_ERR = BIT(21), }; +/* The low 16 bits are for rx data queue indication */ +#define MSIX_FH_INT_CAUSES_DATA_QUEUE 0xffff + /* * Causes for the HW register interrupts */ -- cgit