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: <31df911dc857c59b0d36e586f9542113@milecki.pl>
Date:   Thu, 16 Feb 2017 10:32:52 +0100
From:   Rafał Miłecki <rafal@...ecki.pl>
To:     Arend Van Spriel <arend.vanspriel@...adcom.com>
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 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.