[PATCH] Cache nv to avoid request_firmware on resume path

[Jason Mobarak]

Hello Pontus--

Recently, I saw this oops on a wcn3660 device:
https://gist.github.com/silverjam/434feac44e63eea624f1 ... with lots
of warnings about request_firmware during resume... seems likely this
patch will help with this, yes?

The oops:

[ 1895.207874] [<bf1356b4>] (wcn36xx_remove_interface+0x34/0x64
[wcn36xx]) from [<bf0e3eac>] (__ieee80211_suspend+0x89c/0x9a0
[mac80211])
[ 1895.208331] [<bf0e3eac>] (__ieee80211_suspend+0x89c/0x9a0
[mac80211]) from [<bf009f9c>] (wiphy_suspend+0x120/0x334 [cfg80211])
[ 1895.208484] [<bf009f9c>] (wiphy_suspend+0x120/0x334 [cfg80211])
from [<c03012b4>] (__device_suspend+0x1e4/0x32c)
[ 1895.208514] [<c03012b4>] (__device_suspend+0x1e4/0x32c) from
[<c0301ce0>] (dpm_suspend+0xa8/0x210)
[ 1895.208576] [<c0301ce0>] (dpm_suspend+0xa8/0x210) from [<c00a5c18>]
(suspend_devices_and_enter+0xd4/0x314)
[ 1895.208606] [<c00a5c18>] (suspend_devices_and_enter+0xd4/0x314)
from [<c00a5f78>] (pm_suspend+0x120/0x200)
[ 1895.208667] [<c00a5f78>] (pm_suspend+0x120/0x200) from [<c00a6f20>]
(suspend+0x68/0x180)
[ 1895.208698] [<c00a6f20>] (suspend+0x68/0x180) from [<c0089198>]
(process_one_work+0x280/0x488)
[ 1895.208759] [<c0089198>] (process_one_work+0x280/0x488) from
[<c00895b4>] (worker_thread+0x214/0x3b4)
[ 1895.208789] [<c00895b4>] (worker_thread+0x214/0x3b4) from
[<c008d4cc>] (kthread+0x84/0x90)
[ 1895.208850] [<c008d4cc>] (kthread+0x84/0x90) from [<c000f028>]
(kernel_thread_exit+0x0/0x8)

Thanks,
-Jason


On Fri, Dec 13, 2013 at 12:38 AM, Pontus Fuchs <pontus.fuchs at gmail.com> wrote:
> If wowlan if off mac80211 will stop / start the driver on suspend /
> resume. This causes problems on resume since request_firmware is called
> from start. Fix this by caching the nv.
>
> Signed-off-by: Pontus Fuchs <pontus.fuchs at gmail.com>
> ---
>  main.c    |  2 ++
>  smd.c     | 22 ++++++++++------------
>  wcn36xx.h |  2 ++
>  3 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/main.c b/main.c
> index 7ef1a91..288c282 100644
> --- a/main.c
> +++ b/main.c
> @@ -18,6 +18,7 @@
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
>  #include <linux/module.h>
> +#include <linux/firmware.h>
>  #include <linux/platform_device.h>
>  #include "wcn36xx.h"
>
> @@ -1052,6 +1053,7 @@ static int wcn36xx_remove(struct platform_device *pdev)
>         struct wcn36xx *wcn = hw->priv;
>         wcn36xx_dbg(WCN36XX_DBG_MAC, "platform remove\n");
>
> +       release_firmware(wcn->nv);
>         mutex_destroy(&wcn->hal_mutex);
>
>         ieee80211_unregister_hw(hw);
> diff --git a/smd.c b/smd.c
> index 182c33c..36b8f03 100644
> --- a/smd.c
> +++ b/smd.c
> @@ -247,21 +247,22 @@ static int wcn36xx_smd_rsp_status_check(void *buf, size_t len)
>
>  int wcn36xx_smd_load_nv(struct wcn36xx *wcn)
>  {
> -       const struct firmware *nv;
>         struct nv_data *nv_d;
>         struct wcn36xx_hal_nv_img_download_req_msg msg_body;
>         int fw_bytes_left;
>         int ret;
>         u16 fm_offset = 0;
>
> -       ret = request_firmware(&nv, WLAN_NV_FILE, wcn->dev);
> -       if (ret) {
> -               wcn36xx_err("Failed to load nv file %s: %d\n",
> -                             WLAN_NV_FILE, ret);
> -               goto out_free_nv;
> +       if (!wcn->nv) {
> +               ret = request_firmware(&wcn->nv, WLAN_NV_FILE, wcn->dev);
> +               if (ret) {
> +                       wcn36xx_err("Failed to load nv file %s: %d\n",
> +                                     WLAN_NV_FILE, ret);
> +                       goto out;
> +               }
>         }
>
> -       nv_d = (struct nv_data *)nv->data;
> +       nv_d = (struct nv_data *)wcn->nv->data;
>         INIT_HAL_MSG(msg_body, WCN36XX_HAL_DOWNLOAD_NV_REQ);
>
>         msg_body.header.len += WCN36XX_NV_FRAGMENT_SIZE;
> @@ -271,7 +272,7 @@ int wcn36xx_smd_load_nv(struct wcn36xx *wcn)
>         mutex_lock(&wcn->hal_mutex);
>
>         do {
> -               fw_bytes_left = nv->size - fm_offset - 4;
> +               fw_bytes_left = wcn->nv->size - fm_offset - 4;
>                 if (fw_bytes_left > WCN36XX_NV_FRAGMENT_SIZE) {
>                         msg_body.last_fragment = 0;
>                         msg_body.nv_img_buffer_size = WCN36XX_NV_FRAGMENT_SIZE;
> @@ -309,10 +310,7 @@ int wcn36xx_smd_load_nv(struct wcn36xx *wcn)
>
>  out_unlock:
>         mutex_unlock(&wcn->hal_mutex);
> -out_free_nv:
> -       release_firmware(nv);
> -
> -       return ret;
> +out:   return ret;
>  }
>
>  static int wcn36xx_smd_start_rsp(struct wcn36xx *wcn, void *buf, size_t len)
> diff --git a/wcn36xx.h b/wcn36xx.h
> index 9d217e5..38cf3a7 100644
> --- a/wcn36xx.h
> +++ b/wcn36xx.h
> @@ -172,6 +172,8 @@ struct wcn36xx {
>         struct device           *dev;
>         struct list_head        vif_list;
>
> +       const struct firmware   *nv;
> +
>         u8                      fw_revision;
>         u8                      fw_version;
>         u8                      fw_minor;
> --
> 1.8.3.2
>
>
> _______________________________________________
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> wcn36xx at lists.infradead.org
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