From: Johan Hovold <johan@kernel.org>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-usb@vger.kernel.org, linux-gpio@vger.kernel.org,
linux-kernel@vger.kernel.org,
Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Johan Hovold <johan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
kernel-team@android.com
Subject: Re: [PATCH 3/4] USB: serial: ftdi_sio: Log the CBUS GPIO validity
Date: Mon, 7 Dec 2020 15:29:01 +0100 [thread overview]
Message-ID: <X848LXNv3GRmmSXA@localhost> (raw)
In-Reply-To: <20201204164739.781812-4-maz@kernel.org>
On Fri, Dec 04, 2020 at 04:47:38PM +0000, Marc Zyngier wrote:
> The validity of the ftdi CBUS GPIO is pretty hidden so far,
> and finding out *why* some GPIOs don't work is sometimes
> hard to identify. So let's help the user by displaying the
> map of the CBUS pins that are valid for a GPIO.
>
> Also, tell the user about the magic ftx-prog tool that can
> make GPIOs appear: https://github.com/richardeoin/ftx-prog
>
> Suggested-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/usb/serial/ftdi_sio.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
> index 13e575f16bcd..b9d3b33891fc 100644
> --- a/drivers/usb/serial/ftdi_sio.c
> +++ b/drivers/usb/serial/ftdi_sio.c
> @@ -2012,6 +2012,15 @@ static int ftdi_gpio_init_valid_mask(struct gpio_chip *gc,
>
> bitmap_complement(valid_mask, &map, ngpios);
>
> + if (bitmap_empty(valid_mask, ngpios))
> + dev_warn(&port->dev, "No usable GPIO\n");
This isn't an error of any kind, and certainly not something that
deserves a warning in the system log on every probe. Not everyone cares
about the GPIO interface.
> + else
> + dev_info(&port->dev, "Enabling CBUS%*pbl for GPIO\n",
> + ngpios, valid_mask);
And while printing this mask has some worth I'm still reluctant to be
spamming the logs with it. Just like gpolib has a dev_dbg() for
registering chips, this should probably be demoted to KERN_DEBUG as
well.
> +
> + if (!bitmap_full(valid_mask, ngpios))
> + dev_warn_once(&port->dev, "Consider using a tool such as ftx-prog to enable GPIOs if required\n");
> +
And again, this is not something that belongs in the logs of just about
every system with an attached ftdi device.
While not possible to combine with the valid_mask approach, this is
something which we could otherwise add to the request() callback for the
first request that fails due to the mux configuration.
> return 0;
> }
Johan
next prev parent reply other threads:[~2020-12-07 14:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-04 16:47 [PATCH 0/4] USB: ftdio_sio: GPIO validity fixes Marc Zyngier
2020-12-04 16:47 ` [PATCH 1/4] gpiolib: cdev: Flag invalid GPIOs as used Marc Zyngier
2020-12-07 14:16 ` Johan Hovold
2020-12-07 14:59 ` Marc Zyngier
2020-12-09 9:25 ` Linus Walleij
2020-12-04 16:47 ` [PATCH 2/4] USB: serial: ftdi_sio: Report the valid GPIO lines to gpiolib Marc Zyngier
2020-12-09 9:28 ` Linus Walleij
2020-12-04 16:47 ` [PATCH 3/4] USB: serial: ftdi_sio: Log the CBUS GPIO validity Marc Zyngier
2020-12-07 14:29 ` Johan Hovold [this message]
2020-12-07 15:00 ` Marc Zyngier
2020-12-07 15:19 ` Johan Hovold
2020-12-09 9:35 ` Linus Walleij
2020-12-09 17:05 ` Johan Hovold
2020-12-09 17:39 ` Johan Hovold
2020-12-04 16:47 ` [PATCH 4/4] USB: serial: ftdi_sio: Drop GPIO line checking dead code Marc Zyngier
2020-12-07 9:55 ` [PATCH 0/4] USB: ftdio_sio: GPIO validity fixes Andy Shevchenko
2020-12-07 14:01 ` Johan Hovold
2020-12-07 14:41 ` Marc Zyngier
2020-12-07 15:08 ` Johan Hovold
2020-12-07 15:34 ` Marc Zyngier
2020-12-07 15:49 ` Johan Hovold
2020-12-09 9:20 ` Linus Walleij
2020-12-09 15:42 ` Johan Hovold
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