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From:   Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Date:   Sat, 16 May 2020 10:44:45 +0530
Message-ID: <CAACQVJpqSnTfcb7yvH8vb+L5QzigieQoV=a=1QmH3X8ZEKxBQA@mail.gmail.com>
Subject: Re: [PATCH v2 04/15] bnxt: use new module_firmware_crashed()
To:     Luis Chamberlain <mcgrof@kernel.org>
Cc:     jeyu@kernel.org, akpm@linux-foundation.org, arnd@arndb.de,
        rostedt@goodmis.org, mingo@redhat.com, aquini@redhat.com,
        cai@lca.pw, dyoung@redhat.com, bhe@redhat.com,
        peterz@infradead.org, tglx@linutronix.de, gpiccoli@canonical.com,
        pmladek@suse.com, tiwai@suse.de, schlad@suse.de,
        andriy.shevchenko@linux.intel.com, keescook@chromium.org,
        daniel.vetter@ffwll.ch, will@kernel.org,
        mchehab+samsung@kernel.org, kvalo@codeaurora.org,
        David Miller <davem@davemloft.net>,
        Netdev <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        Michael Chan <michael.chan@broadcom.com>
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On Sat, May 16, 2020 at 3:00 AM Luis Chamberlain <mcgrof@kernel.org> wrote:
>
> This makes use of the new module_firmware_crashed() to help
> annotate when firmware for device drivers crash. When firmware
> crashes devices can sometimes become unresponsive, and recovery
> sometimes requires a driver unload / reload and in the worst cases
> a reboot.
>
> Using a taint flag allows us to annotate when this happens clearly.
>
> Cc: Michael Chan <michael.chan@broadcom.com>
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> index dd0c3f227009..5ba1bd0734e9 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> @@ -3503,6 +3503,7 @@ static int bnxt_get_dump_data(struct net_device *dev, struct ethtool_dump *dump,
>
>         dump->flag = bp->dump_flag;
>         if (dump->flag == BNXT_DUMP_CRASH) {
> +               module_firmware_crashed();
This is not the right place to annotate the taint flag.

Here the driver is just copying the dump after error recovery which is collected
by firmware to DDR, when firmware detects fatal conditions. Driver and firmware
will be healthy when the user calls this command.

Also, users can call this command a thousand times when there is no crash.

I will propose a patch to use this wrapper in the error recovery path,
where the driver
may not be able to recover.

>  #ifdef CONFIG_TEE_BNXT_FW
>                 return tee_bnxt_copy_coredump(buf, 0, dump->len);
>  #endif
> --
> 2.26.2
>
Nacked-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>