Re: [PATCH] brcmfmac: prevent watchdog from interfering with scanning and connecting

From: Arend van Spriel
Date: Thu Jun 19 2014 - 12:38:14 EST


On 19-06-14 18:28, Fu, Zhonghui wrote:

On 2014/6/16 16:15, Arend van Spriel wrote:
On 16-06-14 07:49, Fu, Zhonghui wrote:
From 14485894add32aedacb3e486ebb2cc2b73861abf Mon Sep 17 00:00:00 2001
From: Fu zhonghui <zhonghui.fu@xxxxxxxxxxxxxxx>
Date: Wed, 11 Jun 2014 11:06:55 +0800
Subject: [PATCH] brcmfmac: prevent watchdog from interfering with scanning and connecting

Watchdog in brcmfmac driver may make WiFi chip enter sleep mode
before completion of scanning or connecting.

This will lead to scanning or connecting failure.

Increasing temporarily idle-time threshold during scanning or
connecting can ensure scanning or connecting success without
watchdog interference.

Are you sure you are not having runtime PM enabled. That could be your problem as the host controller code disables sdio irqs. Please see this thread [1]. For our device runtime pm should not be enabled, but I am not sure if that is taken into account in mmc_attach_sdio() (see code below).
I have tried brcmfmac driver with "CONFIG_PM_RUNTIME is not set", and scanning and connecting always succeeded. This means that CONFIG_PM_RUNTIME should not be set if we use SDIO WiFi device driven by brcmfmac driver, right?

Depends which kernel you are using. In 3.16-rc1 the sdio interrupt issue has been fixed so you should be fine to use CONFIG_PM_RUNTIME. Here is the commit

commit be138554a7923658ded799b0e8794d9c1d08a6e5
Author: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Date: Fri Apr 25 12:55:56 2014 +0100

mmc: sdhci: allow sdio interrupts while sdhci runtime suspended

Regards,
Arend

Thanks,
Zhonghui

Gr. AvS

[1] http://www.spinics.net/lists/linux-mmc/msg25978.html

--8<----------------------------------------------------------------

/*
* Enable runtime PM only if supported by host+card+board
*/
if (host->caps & MMC_CAP_POWER_OFF_CARD) {
/*
* Let runtime PM core know our card is active
*/
err = pm_runtime_set_active(&card->dev);
if (err)
goto remove;

/*
* Enable runtime PM for this card
*/
pm_runtime_enable(&card->dev);
}

Signed-off-by: Fu zhonghui <zhonghui.fu@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c | 18 ++++++++++++++++--
.../net/wireless/brcm80211/brcmfmac/wl_cfg80211.c | 3 ++-
2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
index 13c89a0..729deab 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
@@ -34,6 +34,7 @@
#include <linux/vmalloc.h>
#include <linux/platform_data/brcmfmac-sdio.h>
#include <linux/moduleparam.h>
+#include <net/cfg80211.h>
#include <asm/unaligned.h>
#include <defs.h>
#include <brcmu_wifi.h>
@@ -43,6 +44,10 @@
#include "sdio_host.h"
#include "chip.h"
#include "nvram.h"
+#include "dhd.h"
+#include "fwil_types.h"
+#include "p2p.h"
+#include "wl_cfg80211.h"

#define DCMD_RESP_TIMEOUT 2000 /* In milli second */

@@ -307,6 +312,7 @@ struct rte_console {
* when idle
*/
#define BRCMF_IDLE_INTERVAL 1
+#define BRCMF_IDLE_INTERVAL_SCANNING_CONNECTING 100

#define KSO_WAIT_US 50
#define MAX_KSO_ATTEMPTS (PMU_MAX_TRANSITION_DLY/KSO_WAIT_US)
@@ -3613,9 +3619,9 @@ void brcmf_sdio_isr(struct brcmf_sdio *bus)

static bool brcmf_sdio_bus_watchdog(struct brcmf_sdio *bus)
{
-#ifdef DEBUG
struct brcmf_bus *bus_if = dev_get_drvdata(bus->sdiodev->dev);
-#endif /* DEBUG */
+ struct brcmf_cfg80211_info *cfg = bus_if->drvr->config;
+ struct brcmf_if *ifp = cfg->pub->iflist[0];

brcmf_dbg(TIMER, "Enter\n");

@@ -3678,6 +3684,14 @@ static bool brcmf_sdio_bus_watchdog(struct brcmf_sdio *bus)

/* On idle timeout clear activity flag and/or turn off clock */
if ((bus->idletime > 0) && (bus->clkstate == CLK_AVAIL)) {
+
+ if (test_bit(BRCMF_SCAN_STATUS_BUSY, &cfg->scan_status) ||
+ test_bit(BRCMF_VIF_STATUS_CONNECTING, &ifp->vif->sme_state)) {
+ bus->idletime = BRCMF_IDLE_INTERVAL_SCANNING_CONNECTING;
+ } else {
+ bus->idletime = BRCMF_IDLE_INTERVAL;
+ }
+
if (++bus->idlecount >= bus->idletime) {
bus->idlecount = 0;
if (bus->activity) {
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
index be19852..e76517e 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
@@ -913,6 +913,8 @@ brcmf_cfg80211_escan(struct wiphy *wiphy, struct brcmf_cfg80211_vif *vif,
return -EAGAIN;
}

+ set_bit(BRCMF_SCAN_STATUS_BUSY, &cfg->scan_status);
+
/* If scan req comes for p2p0, send it over primary I/F */
if (vif == cfg->p2p.bss_idx[P2PAPI_BSSCFG_DEVICE].vif)
vif = cfg->p2p.bss_idx[P2PAPI_BSSCFG_PRIMARY].vif;
@@ -933,7 +935,6 @@ brcmf_cfg80211_escan(struct wiphy *wiphy, struct brcmf_cfg80211_vif *vif,
}

cfg->scan_request = request;
- set_bit(BRCMF_SCAN_STATUS_BUSY, &cfg->scan_status);
if (escan_req) {
cfg->escan_info.run = brcmf_run_escan;
err = brcmf_p2p_scan_prep(wiphy, request, vif);
-- 1.7.1


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