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Date:   Thu, 20 Aug 2020 01:24:53 +0000
To:     linux-wireless@vger.kernel.org
From:   Connor Davis <connojd@protonmail.com>
Cc:     johannes.berg@intel.com, emmanuel.grumbach@intel.com,
        luciano.coelho@intel.com, linuxwifi@intel.com,
        Connor Davis <connojd@protonmail.com>
Reply-To: Connor Davis <connojd@protonmail.com>
Subject: [PATCH] iwlwifi: mvm: fix RFH_QUEUE_CONFIG_CMD bug
Message-ID: <20200820012022.7504-1-connojd@protonmail.com>
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If iwl_configure_rxq is called when mvm->trans->num_rx_queues =3D=3D 1,
an RFH_QUEUE_CONFIG_CMD is sent with cmd->num_queues =3D=3D 0. This results
in an error when the interface is brought up:

[   10.073760] iwlwifi 0000:3b:00.0: Applying debug destination EXTERNAL_DR=
AM
[   10.239723] iwlwifi 0000:3b:00.0: FW already configured (0) - re-configu=
ring
[   10.441592] iwlwifi 0000:3b:00.0: Microcode SW error detected.  Restarti=
ng 0x2000000.
[   10.442812] iwlwifi 0000:3b:00.0: Start IWL Error Log Dump:
[   10.442815] iwlwifi 0000:3b:00.0: Status: 0x00000040, count: 6
[   10.442817] iwlwifi 0000:3b:00.0: Loaded firmware version: 48.4fa0041f.0=
 cc-a0-48.ucode
[   10.442818] iwlwifi 0000:3b:00.0: 0x00000071 | NMI_INTERRUPT_UMAC_FATAL
[   10.442820] iwlwifi 0000:3b:00.0: 0x000022F0 | trm_hw_status0
[   10.442821] iwlwifi 0000:3b:00.0: 0x00000000 | trm_hw_status1
[   10.442822] iwlwifi 0000:3b:00.0: 0x004F8E3C | branchlink2
[   10.442823] iwlwifi 0000:3b:00.0: 0x004E4FF4 | interruptlink1
[   10.442825] iwlwifi 0000:3b:00.0: 0x004E4FF4 | interruptlink2
[   10.442826] iwlwifi 0000:3b:00.0: 0x00016FF4 | data1
[   10.442827] iwlwifi 0000:3b:00.0: 0x00001000 | data2
[   10.442828] iwlwifi 0000:3b:00.0: 0xF0000008 | data3
[   10.442829] iwlwifi 0000:3b:00.0: 0x00000000 | beacon time
[   10.442831] iwlwifi 0000:3b:00.0: 0x00053105 | tsf low
[   10.442832] iwlwifi 0000:3b:00.0: 0x00000000 | tsf hi
[   10.442833] iwlwifi 0000:3b:00.0: 0x00000000 | time gp1
[   10.442834] iwlwifi 0000:3b:00.0: 0x00059A51 | time gp2
[   10.442835] iwlwifi 0000:3b:00.0: 0x00000001 | uCode revision type
[   10.442836] iwlwifi 0000:3b:00.0: 0x00000030 | uCode version major
[   10.442838] iwlwifi 0000:3b:00.0: 0x4FA0041F | uCode version minor
[   10.442839] iwlwifi 0000:3b:00.0: 0x00000340 | hw version
[   10.442840] iwlwifi 0000:3b:00.0: 0x18C89000 | board version
[   10.442841] iwlwifi 0000:3b:00.0: 0x801FF500 | hcmd
[   10.442842] iwlwifi 0000:3b:00.0: 0x00020000 | isr0
[   10.442843] iwlwifi 0000:3b:00.0: 0x00000000 | isr1
[   10.442845] iwlwifi 0000:3b:00.0: 0x08F00002 | isr2
[   10.442846] iwlwifi 0000:3b:00.0: 0x00C00008 | isr3
[   10.442847] iwlwifi 0000:3b:00.0: 0x00000000 | isr4
[   10.442848] iwlwifi 0000:3b:00.0: 0x000301D1 | last cmd Id
[   10.442849] iwlwifi 0000:3b:00.0: 0x00016FF4 | wait_event
[   10.442850] iwlwifi 0000:3b:00.0: 0x00000000 | l2p_control
[   10.442851] iwlwifi 0000:3b:00.0: 0x00000000 | l2p_duration
[   10.442852] iwlwifi 0000:3b:00.0: 0x00000000 | l2p_mhvalid
[   10.442853] iwlwifi 0000:3b:00.0: 0x00000000 | l2p_addr_match
[   10.442855] iwlwifi 0000:3b:00.0: 0x00000009 | lmpm_pmg_sel
[   10.442856] iwlwifi 0000:3b:00.0: 0x00000000 | timestamp
[   10.442857] iwlwifi 0000:3b:00.0: 0x00000828 | flow_handler
[   10.443452] iwlwifi 0000:3b:00.0: Start IWL Error Log Dump:
[   10.443453] iwlwifi 0000:3b:00.0: Status: 0x00000040, count: 7
[   10.443454] iwlwifi 0000:3b:00.0: 0x20000034 | NMI_INTERRUPT_WDG
[   10.443456] iwlwifi 0000:3b:00.0: 0x00000000 | umac branchlink1
[   10.443456] iwlwifi 0000:3b:00.0: 0xC008CC3C | umac branchlink2
[   10.443458] iwlwifi 0000:3b:00.0: 0x8048E6D8 | umac interruptlink1
[   10.443459] iwlwifi 0000:3b:00.0: 0x8048E6D8 | umac interruptlink2
[   10.443460] iwlwifi 0000:3b:00.0: 0x00000004 | umac data1
[   10.443461] iwlwifi 0000:3b:00.0: 0x8048E6D8 | umac data2
[   10.443462] iwlwifi 0000:3b:00.0: 0x00000000 | umac data3
[   10.443463] iwlwifi 0000:3b:00.0: 0x00000030 | umac major
[   10.443464] iwlwifi 0000:3b:00.0: 0x4FA0041F | umac minor
[   10.443465] iwlwifi 0000:3b:00.0: 0x00059A43 | frame pointer
[   10.443466] iwlwifi 0000:3b:00.0: 0xC0886A48 | stack pointer
[   10.443468] iwlwifi 0000:3b:00.0: 0x000B050D | last host cmd
[   10.443469] iwlwifi 0000:3b:00.0: 0x00000000 | isr status reg
[   10.443553] iwlwifi 0000:3b:00.0: Fseq Registers:
[   10.443605] iwlwifi 0000:3b:00.0: 0xE0000101 | FSEQ_ERROR_CODE
[   10.443657] iwlwifi 0000:3b:00.0: 0x00290011 | FSEQ_TOP_INIT_VERSION
[   10.443709] iwlwifi 0000:3b:00.0: 0x80050008 | FSEQ_CNVIO_INIT_VERSION
[   10.443775] iwlwifi 0000:3b:00.0: 0x0000A503 | FSEQ_OTP_VERSION
[   10.443912] iwlwifi 0000:3b:00.0: 0x80000003 | FSEQ_TOP_CONTENT_VERSION
[   10.443958] iwlwifi 0000:3b:00.0: 0x4552414E | FSEQ_ALIVE_TOKEN
[   10.444011] iwlwifi 0000:3b:00.0: 0x00100530 | FSEQ_CNVI_ID
[   10.444062] iwlwifi 0000:3b:00.0: 0x00000532 | FSEQ_CNVR_ID
[   10.444113] iwlwifi 0000:3b:00.0: 0x00100530 | CNVI_AUX_MISC_CHIP
[   10.444166] iwlwifi 0000:3b:00.0: 0x00000532 | CNVR_AUX_MISC_CHIP
[   10.444220] iwlwifi 0000:3b:00.0: 0x05B0905B | CNVR_SCU_SD_REGS_SD_REG_D=
IG_DCDC_VTRIM
[   10.444275] iwlwifi 0000:3b:00.0: 0x0000025B | CNVR_SCU_SD_REGS_SD_REG_A=
CTIVE_VDIG_MIRROR
[   10.445696] iwlwifi 0000:3b:00.0: Collecting data: trigger 2 fired.
[   10.445710] iwlwifi 0000:3b:00.0: FW error in SYNC CMD RFH_QUEUE_CONFIG_=
CMD
[   10.445873] iwlwifi 0000:3b:00.0: Failed to configure RX queues: -5

that has been seen on several AX200/9462 devices running in a Xen HVM domai=
n
with PCI passthrough [0][1]. It can also be seen natively with a Killer AX1=
650x
by coaxing the value of num_rx_queues to 1 in iwl_pcie_set_interrupt_capa.

Fix this by returning early from iwl_configure_rxq whenever num_rx_queues i=
s 1.

[0] https://github.com/QubesOS/qubes-issues/issues/5616
[1] https://lore.kernel.org/linux-wireless/3cab5072-17a2-4d9a-2077-93788971=
c6c4@invisiblethingslab.com/T/

Signed-off-by: Connor Davis <connojd@protonmail.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/fw.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wire=
less/intel/iwlwifi/mvm/fw.c
index 95a613537047..36066a11f835 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -132,6 +132,9 @@ static int iwl_configure_rxq(struct iwl_mvm *mvm)
 =09=09.dataflags[0] =3D IWL_HCMD_DFL_NOCOPY,
 =09};
=20
+=09if (mvm->trans->num_rx_queues =3D=3D 1)
+=09=09return 0;
+
 =09/* Do not configure default queue, it is configured via context info */
 =09num_queues =3D mvm->trans->num_rx_queues - 1;
=20
--=20
2.25.1