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

From: "Fu, Zhonghui" <[email-masked]>
Date: Mon, 21 Jul 2014 15:42:04 +0800

On 2014/6/20 0:37, Arend van Spriel wrote:
> 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

I run 3.16-rc4 and 3.16-rc5 kernel with CONFIG_PM_RUNTIME set, the issue still exists as follows:

1 step: modprobe brcmfmac
2 step: iwlist wlan1 scan         get scanning result successfully.
3 step: wait a while, no any operation
4 step: iwlist wlan1 scan         scanning timeout, can't get scanning result.

Thanks,
Zhonghui

>
> 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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>
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