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

From: Arend van Spriel <[email-masked]>
Date: Thu, 19 Jun 2014 18:37:56 +0200

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 <[email-masked]>
>>> 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 <[email-masked]>
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 <[email-masked]>
>>> ---
>>>    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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>