2020-09-11 09:40:43

by Hsin-Yi Wang

Subject: [PATCH 1/2] tty: serial: print earlycon info after match->setup

8250 devices may modify iotype in their own earlycon setup. For example:
8250_mtk and 8250_uniphier force iotype to be MMIO32. Print earlycon info
after match->setup to reflect actual earlycon info.

Signed-off-by: Hsin-Yi Wang <[email protected]>
---
drivers/tty/serial/earlycon.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 2ae9190b64bb9..22f0876f72d49 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -56,7 +56,6 @@ static void __init earlycon_init(struct earlycon_device *device,
const char *name)
{
struct console *earlycon = device->con;
- struct uart_port *port = &device->port;
const char *s;
size_t len;

@@ -70,6 +69,12 @@ static void __init earlycon_init(struct earlycon_device *device,
len = s - name;
strlcpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
earlycon->data = &early_console_dev;
+}
+
+static void __init earlycon_info(struct earlycon_device *device)
+{
+ struct console *earlycon = device->con;
+ struct uart_port *port = &device->port;

if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM16 ||
port->iotype == UPIO_MEM32 || port->iotype == UPIO_MEM32BE)
@@ -140,6 +145,7 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)

earlycon_init(&early_console_dev, match->name);
err = match->setup(&early_console_dev, buf);
+ earlycon_info(&early_console_dev);
if (err < 0)
return err;
if (!early_console_dev.con->write)
@@ -302,6 +308,7 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
}
earlycon_init(&early_console_dev, match->name);
err = match->setup(&early_console_dev, options);
+ earlycon_info(&early_console_dev);
if (err < 0)
return err;
if (!early_console_dev.con->write)
--
2.28.0.618.gf4bc123cb7-goog

2020-09-11 09:41:36

by Hsin-Yi Wang

Subject: [PATCH 2/2] tty: serial: 8250_mtk: set regshift for mmio32

To use mmio32, we also need to set regshift.

Signed-off-by: Hsin-Yi Wang <[email protected]>
---
drivers/tty/serial/8250/8250_mtk.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 7b0dec14c8b80..41f4120abdf29 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -669,6 +669,7 @@ static int __init early_mtk8250_setup(struct earlycon_device *device,
return -ENODEV;

device->port.iotype = UPIO_MEM32;
+ device->port.regshift = 2;

return early_serial8250_setup(device, NULL);
}
--
2.28.0.618.gf4bc123cb7-goog

2020-09-14 16:11:36

by Andy Shevchenko

Subject: Re: [PATCH 1/2] tty: serial: print earlycon info after match->setup

On Fri, Sep 11, 2020 at 05:39:26PM +0800, Hsin-Yi Wang wrote:
> 8250 devices may modify iotype in their own earlycon setup. For example:
> 8250_mtk and 8250_uniphier force iotype to be MMIO32. Print earlycon info
> after match->setup to reflect actual earlycon info.

But this means you do something which user didn't ask for...

> +static void __init earlycon_info(struct earlycon_device *device)

Can it be earlycon_pr_info() or earlycon_print_info() ?

--
With Best Regards,
Andy Shevchenko

2020-09-14 17:29:33

by Hsin-Yi Wang

Subject: Re: [PATCH 1/2] tty: serial: print earlycon info after match->setup

On Tue, Sep 15, 2020 at 12:06 AM Andy Shevchenko
<[email protected]> wrote:
>
> On Fri, Sep 11, 2020 at 05:39:26PM +0800, Hsin-Yi Wang wrote:
> > 8250 devices may modify iotype in their own earlycon setup. For example:
> > 8250_mtk and 8250_uniphier force iotype to be MMIO32. Print earlycon info
> > after match->setup to reflect actual earlycon info.
>
> But this means you do something which user didn't ask for...
>
8250_uniphier states that it can only use mmio32
https://elixir.bootlin.com/linux/v5.9-rc4/source/drivers/tty/serial/8250/8250_uniphier.c#L46

For MTK, may be the same case. So they are set in the driver.

> > +static void __init earlycon_info(struct earlycon_device *device)
>
> Can it be earlycon_pr_info() or earlycon_print_info() ?
>
Sure. I'll send a v2.

> --
> With Best Regards,
> Andy Shevchenko
>
>