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

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Date:   Thu, 16 Feb 2017 11:17:57 +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 10:32, Rafał Miłecki wrote:
> On 2017-02-16 10:18, Arend Van Spriel wrote:
>> 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.
> 
> Drivers always got a choice (see bool uevent) so I didn't want to change
> it.

Sure, I know. I just wanted to vent an opinion for the firmware_class
maintainers.

Regards,
Arend