linux-kernel - [PATCH AUTOSEL 5.1 184/219] iwlwifi: dbg: fix debug monitor stop and restart delays

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Date:   Mon, 15 Jul 2019 10:03:05 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Shahar S Matityahu <shahar.s.matityahu@...el.com>,
        Luca Coelho <luciano.coelho@...el.com>,
        Sasha Levin <sashal@...nel.org>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH AUTOSEL 5.1 184/219] iwlwifi: dbg: fix debug monitor stop and restart delays

From: Shahar S Matityahu <shahar.s.matityahu@...el.com>

[ Upstream commit fc838c775f35e272e5cc7ef43853f0b55babbe37 ]

The driver should delay only in recording stop flow between writing to
DBGC_IN_SAMPLE register and DBGC_OUT_CTRL register. Any other delay is
not needed.

Change the following:
1. Remove any unnecessary delays in the flow
2. Increase the delay in the stop recording flow since 100 micro is
   not enough
3. Use usleep_range instead of delay since the driver is allowed to
   sleep in this flow.

Signed-off-by: Shahar S Matityahu <shahar.s.matityahu@...el.com>
Fixes: 5cfe79c8d92a ("iwlwifi: fw: stop and start debugging using host command")
Signed-off-by: Luca Coelho <luciano.coelho@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/wireless/intel/iwlwifi/fw/dbg.c | 2 --
 drivers/net/wireless/intel/iwlwifi/fw/dbg.h | 6 ++++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
index d7380016f1c0..c30f626b1602 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
@@ -2146,8 +2146,6 @@ void iwl_fw_dbg_collect_sync(struct iwl_fw_runtime *fwrt)
 	/* start recording again if the firmware is not crashed */
 	if (!test_bit(STATUS_FW_ERROR, &fwrt->trans->status) &&
 	    fwrt->fw->dbg.dest_tlv) {
-		/* wait before we collect the data till the DBGC stop */
-		udelay(500);
 		iwl_fw_dbg_restart_recording(fwrt, &params);
 	}
 }
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.h b/drivers/net/wireless/intel/iwlwifi/fw/dbg.h
index a199056234d3..97fcd57e17d8 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.h
@@ -297,7 +297,10 @@ _iwl_fw_dbg_stop_recording(struct iwl_trans *trans,
 	}
 
 	iwl_write_umac_prph(trans, DBGC_IN_SAMPLE, 0);
-	udelay(100);
+	/* wait for the DBGC to finish writing the internal buffer to DRAM to
+	 * avoid halting the HW while writing
+	 */
+	usleep_range(700, 1000);
 	iwl_write_umac_prph(trans, DBGC_OUT_CTRL, 0);
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 	trans->dbg_rec_on = false;
@@ -327,7 +330,6 @@ _iwl_fw_dbg_restart_recording(struct iwl_trans *trans,
 		iwl_set_bits_prph(trans, MON_BUFF_SAMPLE_CTL, 0x1);
 	} else {
 		iwl_write_umac_prph(trans, DBGC_IN_SAMPLE, params->in_sample);
-		udelay(100);
 		iwl_write_umac_prph(trans, DBGC_OUT_CTRL, params->out_ctrl);
 	}
 }
-- 
2.20.1