linux-kernel - Re: [PATCH V2 2/2] brcmfmac: don't warn user about NVRAM if fallback to platform one succeeds

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Message-ID: <88182ec9-3344-7468-d3c3-33d9ffa532e2@broadcom.com>
Date:   Thu, 16 Feb 2017 10:18:11 +0100
From:   Arend Van Spriel <arend.vanspriel@...adcom.com>
To:     Rafał Miłecki <rafal@...ecki.pl>
Cc:     Rafał Miłecki <zajec5@...il.com>,
        Ming Lei <ming.lei@...onical.com>,
        "Luis R . Rodriguez" <mcgrof@...nel.org>,
        Greg KH <gregkh@...uxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Kalle Valo <kvalo@...eaurora.org>,
        linux-wireless@...r.kernel.org, brcm80211-dev-list.pdl@...adcom.com
Subject: Re: [PATCH V2 2/2] brcmfmac: don't warn user about NVRAM if fallback
 to platform one succeeds

On 16-2-2017 10:04, Rafał Miłecki wrote:
> On 2017-02-16 09:38, Arend Van Spriel wrote:
>> On 16-2-2017 8:26, Rafał Miłecki wrote:
>>> From: Rafał Miłecki <rafal@...ecki.pl>
>>>
>>> Failing to load NVRAM file isn't critical if we manage to get platform
>>> one in the fallback path. It means warnings like:
>>> [   10.801506] brcmfmac 0000:01:00.0: Direct firmware load for
>>> brcm/brcmfmac43602-pcie.txt failed with error -2
>>> are unnecessary & disturbing for people with platform NVRAM. This is
>>> very common case for Broadcom home routers.
>>>
>>> So instead of printing warning immediately with the firmware subsystem
>>> let's first try our fallback code. If that fails as well, then it's a
>>> right moment to print an error.
>>>
>>> This should reduce amount of false reports from users seeing this
>>> warning while having wireless working perfectly fine.
>>
>> There are of course people with issues who take this warning as a straw
>> to clutch.
>>
>>> Signed-off-by: Rafał Miłecki <rafal@...ecki.pl>
>>> ---
>>> V2: Update commit message as it wasn't clear enough (thanks Andy) &
>>> add extra
>>>     messages to the firmware.c.
>>>
>>> Kalle, Arend: this patch is strictly related to the bigger 1/2. Could
>>> you ack
>>> this change as I expect this patchset to be picked by Ming, Luis or
>>> Greg?
>>> ---
>>>  .../net/wireless/broadcom/brcm80211/brcmfmac/firmware.c  | 16
>>> +++++++++++-----
>>>  1 file changed, 11 insertions(+), 5 deletions(-)
>>>
>>> diff --git
>>> a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
>>> b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
>>> index c7c1e9906500..510a76d99eee 100644
>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
>>> @@ -462,8 +462,14 @@ static void brcmf_fw_request_nvram_done(const
>>> struct firmware *fw, void *ctx)
>>>          raw_nvram = false;
>>>      } else {
>>>          data = bcm47xx_nvram_get_contents(&data_len);
>>> -        if (!data && !(fwctx->flags & BRCMF_FW_REQ_NV_OPTIONAL))
>>> -            goto fail;
>>> +        if (!data) {
>>> +            brcmf_dbg(TRACE, "Failed to get platform NVRAM\n");
>>> +            if (!(fwctx->flags & BRCMF_FW_REQ_NV_OPTIONAL)) {
>>> +                brcmf_err("Loading NVRAM from %s and using platform
>>> one both failed\n",
>>> +                      fwctx->nvram_name);
>>> +                goto fail;
>>> +            }
>>> +        }
>>>          raw_nvram = true;
>>>      }
>>>
>>> @@ -504,9 +510,9 @@ static void brcmf_fw_request_code_done(const
>>> struct firmware *fw, void *ctx)
>>>          return;
>>>      }
>>>      fwctx->code = fw;
>>> -    ret = request_firmware_nowait(THIS_MODULE, true, fwctx->nvram_name,
>>> -                      fwctx->dev, GFP_KERNEL, fwctx,
>>> -                      brcmf_fw_request_nvram_done);
>>> +    ret = request_firmware_async(THIS_MODULE, FW_OPT_NO_WARN,
>>> +                     fwctx->nvram_name, fwctx->dev, GFP_KERNEL,
>>> +                     fwctx, brcmf_fw_request_nvram_done);
>>
>> You changed the behaviour, because of your change in patch 1/2:
>>
>> -    fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
>> -        (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
>> +    fw_work->opt_flags = FW_OPT_NOWAIT | opt_flags;
>>
>> So: (FW_OPT_NOWAIT | FW_OPT_UEVENT) vs (FW_OPT_NOWAIT | FW_OPT_NO_WARN)
> 
> Sorry, I didn't realize brcmfmac needs FW_OPT_UEVENT. I'll re-add it in
> V3, just
> let me wait to see if there will be more comments.

To be honest whether or not FW_OPT_UEVENT is needed should not be
something a driver needs to concern about. It is really a system
configuration issue if you ask me. So the only thing we could do is to
have it just in case.

Regards,
Arend