On Mon, 31 Jul 2023 17:55:42 +0200
Greg KH [off-list ref] wrote:

On Tue, Jul 25, 2023 at 10:23:36AM -0400, Hugo Villeneuve wrote:

quoted

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

In preparation for upcoming patch "fix regression with GPIO
configuration". To facilitate review and make code more modular.

I would much rather the issue be fixed _before_ the code is refactored,
unless it is impossible to fix it without the refactor?

Hi Greg,
normally I would agree, but the refactor in this case helps a lot to
address some issues raised by you and Andy in V7 of this series.

Maybe I could merge it with the actual patch "fix regression with GPIO
configuration"?

quoted

Cc: <redacted> # 6.1.x

What commit id does this fix?

It doesn't fix anything, but I tought that I needed this tag since
this patch is a prerequisite for the next patch in the series, which
would be applied to stable kernels. I will remove this tag (assuming
the patch stays as it is, depending on your answer to the above
question).

 

quoted

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Lech Perczak <redacted>
Tested-by: Lech Perczak <redacted>
---
 drivers/tty/serial/sc16is7xx.c | 40 ++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 32d43d00a583..5b0aeef9d534 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c

@@ -332,6 +332,7 @@ struct sc16is7xx_one {
 
 struct sc16is7xx_port {
 	const struct sc16is7xx_devtype	*devtype;
+	struct device			*dev;

Why is this pointer needed?

Why is it grabbed and yet the reference count is never incremented?  Who
owns the reference count and when will it go away?

And what device is this?  The parent?  Current device?  What type of
device is it?  And why is it needed?

Using "raw" devices is almost never something a driver should do, they
are only passed into functions by the driver core, but then the driver
should instantly turn them into the "real" structure.

We already discussed that a lot in previous versions (v7)... I am
trying my best to modify the code to address your concerns, but I am
not fully understanding what you mean about raw devices, and you didn't
answer some of my previous questions/interrogations in v7 about that.

So, in the new function that I
need to implement, sc16is7xx_setup_gpio_chip(), I absolutely need to use
a raw device to read a device tree property and to set
s->gpio.parent:

    count = device_property_count_u32(dev, ...
    ...
    s->gpio.parent = dev;

Do we agree on that?

Then, how do I pass this raw device to the 
device_property_count_u32() function and to the s->gpio.parent
assignment?

Should I modify sc16is7xx_setup_gpio_chip() like so:

    static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
    {
	struct device *dev = &s->p[0].port.dev;

        count = device_property_count_u32(dev, ...
        ...
        s->gpio.parent = dev;

?

If not, can you show me how you would like to do it to avoid me trying
to guess?

Thank you,
Hugo.