From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iRZMj-0004x0-Nw for barebox@lists.infradead.org; Mon, 04 Nov 2019 10:13:43 +0000 Date: Mon, 4 Nov 2019 11:13:40 +0100 From: Marco Felsch Message-ID: <20191104101340.dp4oalzd75nei3md@pengutronix.de> References: <20191030170653.5559-1-m.felsch@pengutronix.de> <20191030170653.5559-2-m.felsch@pengutronix.de> <20191104082723.uyjfis5syqfrtqr6@pengutronix.de> <20191104083445.jtympksioikrvjyx@pengutronix.de> <2d52df4c-9501-01a2-d67e-3086c1538bdb@pengutronix.de> <20191104094452.xxpoqvm6d33h4wnh@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 2/2] mfd: da9063: fix watchdog ping execution To: Ahmad Fatoum Cc: barebox@lists.infradead.org Hi Ahmad, On 19-11-04 10:57, Ahmad Fatoum wrote: > Hello Marco, > > On 11/4/19 10:44 AM, Marco Felsch wrote: > >> This means that your boot time would increase by 200 ms. If this matter to you, > >> you might want to change this, so watchdog_set_timeout is called only once. > > > > Increasing the delay isn't a big deal. But after we discussed it again I > > will send a v2 which handles the to fast pings by dropping those. > > That would be an option too, but moving watchdog_set_timeout out of boot_entry > would benefit other platforms too. Hm.. I don't have a strong opinion about that. To me it seems correct to handle the boot-watchdog within the boot_entry() function and the callers don't need to setup it. Anyway v2 is coming ;) Regards, Marco > >> And if you do so, you could drop this patch. The only other places that feed > >> the watchdog are the watchdog poller and the wd command. The watchdog poller > >> already waits 500 ms between pings and the command is meant for debugging/testing. > >> If someone wants to feed the watchdog that fast while testing, why prevent them? > > > > Becuase if the watchdog gets feeded to fast then the system gets > > reseted. So dropping the patch isn't a option. > > If you move watchdog_set_timeout out of boot_entry, you'll only be able to feed the > watchdog too fast if you manually type wd 1; wd 1;, which I argue isn't really an issue > IMHO, but I am fine with what you implement either way. > > > > >> (I assume you don't need to wait 200 ms between ping and disabling WDT, if you do, > >> one more place is the .priority watchdog device parameter in barebox-next > > > > Sorry, I don't get this. You don't need to wait 200ms between ping and > > disabling. > > Just wanted to make sure that disabling the watchdog twice in rapdi succession doesn't > trigger the issue as well. All good. > > Cheers > Ahmad > > > > > Regards, > > Marco > > > >> Cheers > >> Ahmad > >> > >>>>> > >>>>> Signed-off-by: Marco Felsch > >>>>> --- > >>>>> drivers/mfd/da9063.c | 11 +++++++++++ > >>>>> 1 file changed, 11 insertions(+) > >>>>> > >>>>> diff --git a/drivers/mfd/da9063.c b/drivers/mfd/da9063.c > >>>>> index 4d459c7f18..ab57885240 100644 > >>>>> --- a/drivers/mfd/da9063.c > >>>>> +++ b/drivers/mfd/da9063.c > >>>>> @@ -14,6 +14,7 @@ > >>>>> */ > >>>>> > >>>>> #include > >>>>> +#include > >>>>> #include > >>>>> #include > >>>>> #include > >>>>> @@ -33,6 +34,7 @@ struct da9063 { > >>>>> struct i2c_client *client1; > >>>>> struct device_d *dev; > >>>>> unsigned int timeout; > >>>>> + uint64_t last_ping; > >>>>> }; > >>>>> > >>>>> /* forbidden/impossible value; timeout will be set to this value initially to > >>>>> @@ -237,6 +239,13 @@ static int da9063_watchdog_ping(struct da9063 *priv) > >>>>> int ret; > >>>>> u8 val; > >>>>> > >>>>> + /* We need to wait at least 200ms till we can resend a ping */ > >>>>> + if (!is_timeout_non_interruptible(priv->last_ping, 200 * MSECOND)) { > >>>>> + dev_dbg(priv->dev, "active ping delay\n"); > >>>>> + mdelay(50); > >>>> > >>>> I would expect to wait the missing time to 200ms here. Maybe doing > >>>> nothing in this case would be more appropriate here. I mean, why should > >>>> you slow down barebox here when some code triggers the watchdog too > >>>> often? > >>>> > >>>>> + return da9063_watchdog_ping(priv); > >>>> > >>>> Drop this, just fall through. > >>> > >>> Just prepared a v2 with a busy wait after discussed it with Lucas. > >>> Thanks for your input too :) > >>> > >>> Regards, > >>> Marco > >>> > >>>> Sascha > >>>> > >>>> -- > >>>> Pengutronix e.K. | | > >>>> Industrial Linux Solutions | http://www.pengutronix.de/ | > >>>> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > >>>> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > >>>> > >>> > >> > >> -- > >> Pengutronix e.K. | | > >> Industrial Linux Solutions | http://www.pengutronix.de/ | > >> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > >> > > > > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox