From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Cc: linux-kernel@vger.kernel.org,
Amarula patchwork <linux-amarula@amarulasolutions.com>,
michael@amarulasolutions.com,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jakub Kicinski <kuba@kernel.org>,
Jiri Slaby <jirislaby@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
Wolfgang Grandegger <wg@grandegger.com>,
linux-can@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [RFC PATCH 11/13] can: slcan: add ethtool support to reset adapter errors
Date: Thu, 9 Jun 2022 10:01:12 +0200 [thread overview]
Message-ID: <20220609080112.24bw2764ov767pqc@pengutronix.de> (raw)
In-Reply-To: <CABGWkvrViDyWfU=PUfKq2HXnDjhiZdOMWSBt3xcmxFKxhHKCyw@mail.gmail.com>
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On 09.06.2022 09:24:14, Dario Binacchi wrote:
> > > > I'm a big fan of bringing the device into a well known good state during
> > > > ifup. What would be the reasons/use cases to not reset the device?
> > >
> > > Because by default either slcand and slcan_attach don't reset the
> > > error states, but you must use the `-f' option to do so. So, I
> > > followed this use case.
> >
> > Is this a CAN bus error state, like Bus Off or some controller (i.e. non
> > CAN related) error?
>
> The help option of slcan_attach and slcand prints " -f (read status
> flags with 'F\\r' to reset error states)\n" I looked at the sources of
> the adapter I am using (USBtin, which uses the mcp2515 controller).
> The 'F' command reads the EFLG register (0x2d) without resetting the
> RX0OVR and RX1OVR overrun bits.
The Lawicel doc [1] says 'F' is to read the status flags not to clear
it. However commit 7ef581fec029 ("slcan_attach: added '-f' commandline
option to read status flags") [2] suggests that there are some adapters
that the reading of the status flag clears the errors. IMHO the 'F'
command should be send unconditionally during open.
[1] http://www.can232.com/docs/can232_v3.pdf
[2] https://github.com/linux-can/can-utils/commit/7ef581fec0298a228baa71372ea5667874fb4a56
> The error states reset is done by 'f <subcmd>' command, that is not
> managed by slcan_attach/slcand.
Is the 'f' command is non-standard?
> switch (subcmd) {
> case 0x0: // Disable status reporting
> mcp2515_write_register(MCP2515_REG_CANINTE, 0x00);
> return CR;
> case 0x1: // Enable status reporting
> mcp2515_write_register(MCP2515_REG_CANINTE, 0x20); //
> ERRIE interrupt to INT pin
> return CR;
> case 0x2: // Clear overrun errors
> mcp2515_write_register(MCP2515_REG_EFLG, 0x00);
> return CR;
> case 0x3: // Reinit/reset MCP2515 to clear all errors
> if (state == STATE_CONFIG) {
> mcp2515_init();
> return CR;
> }
> break;
> }
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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next prev parent reply other threads:[~2022-06-09 8:01 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-07 9:47 [RFC PATCH 00/13] can: slcan: extend supported features Dario Binacchi
2022-06-07 9:47 ` [RFC PATCH 01/13] can: slcan: use the BIT() helper Dario Binacchi
2022-06-07 9:47 ` [RFC PATCH 02/13] can: slcan: use netdev helpers to print out messages Dario Binacchi
2022-06-07 9:47 ` [RFC PATCH 03/13] can: slcan: use the alloc_can_skb() helper Dario Binacchi
2022-06-07 10:15 ` Marc Kleine-Budde
2022-06-07 9:47 ` [RFC PATCH 04/13] can: slcan: use CAN network device driver API Dario Binacchi
2022-06-07 11:13 ` Marc Kleine-Budde
2022-06-08 16:42 ` Dario Binacchi
2022-06-09 7:07 ` Marc Kleine-Budde
2022-06-12 21:24 ` Dario Binacchi
2022-06-07 9:47 ` [RFC PATCH 05/13] can: slcan: simplify the device de-allocation Dario Binacchi
2022-06-07 20:45 ` Oliver Hartkopp
2022-06-07 9:47 ` [RFC PATCH 06/13] can: slcan: allow to send commands to the adapter Dario Binacchi
2022-06-09 7:16 ` Marc Kleine-Budde
2022-06-11 21:43 ` Dario Binacchi
2022-06-12 10:39 ` Marc Kleine-Budde
2022-06-07 9:47 ` [RFC PATCH 07/13] can: slcan: set bitrate by CAN device driver API Dario Binacchi
2022-06-07 10:09 ` Marc Kleine-Budde
2022-06-07 9:47 ` [RFC PATCH 08/13] can: slcan: send the open command to the adapter Dario Binacchi
2022-06-07 11:00 ` Marc Kleine-Budde
2022-06-07 9:47 ` [RFC PATCH 09/13] can: slcan: send the close " Dario Binacchi
2022-06-07 9:47 ` [RFC PATCH 10/13] can: slcan: move driver into separate sub directory Dario Binacchi
2022-06-07 9:47 ` [RFC PATCH 11/13] can: slcan: add ethtool support to reset adapter errors Dario Binacchi
2022-06-07 10:52 ` Marc Kleine-Budde
2022-06-08 16:33 ` Dario Binacchi
2022-06-09 6:38 ` Marc Kleine-Budde
2022-06-09 7:24 ` Dario Binacchi
2022-06-09 8:01 ` Marc Kleine-Budde [this message]
2022-06-09 8:52 ` Dario Binacchi
2022-06-10 10:51 ` Marc Kleine-Budde
2022-06-07 9:47 ` [RFC PATCH 12/13] can: slcan: extend the protocol with error info Dario Binacchi
2022-06-07 10:56 ` Marc Kleine-Budde
2022-06-07 9:47 ` [RFC PATCH 13/13] can: slcan: extend the protocol with CAN state info Dario Binacchi
2022-06-07 10:13 ` Marc Kleine-Budde
2022-06-07 10:27 ` [RFC PATCH 00/13] can: slcan: extend supported features Vincent MAILHOL
2022-06-07 10:39 ` Marc Kleine-Budde
2022-06-07 12:20 ` Vincent MAILHOL
2022-06-07 12:19 ` Vincent MAILHOL
2022-06-07 23:55 ` Max Staudt
2022-06-08 0:15 ` Max Staudt
2022-06-08 7:19 ` Marc Kleine-Budde
2022-06-08 12:55 ` Max Staudt
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