diff mbox

[v3,3/3] of: support passing console options with stdout-path

Message ID 1417110967-16284-4-git-send-email-leif.lindholm@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Leif Lindholm Nov. 27, 2014, 5:56 p.m. UTC
Support specifying console options (like with console=ttyXN,<options>)
by appending them to the stdout-path property after a separating ':'.

Example:
        stdout-path = "uart0:115200";

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
---
 drivers/of/base.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Grant Likely Nov. 28, 2014, 3:39 p.m. UTC | #1
On Thu, 27 Nov 2014 17:56:07 +0000
, Leif Lindholm <leif.lindholm@linaro.org>
 wrote:
> Support specifying console options (like with console=ttyXN,<options>)
> by appending them to the stdout-path property after a separating ':'.
> 
> Example:
>         stdout-path = "uart0:115200";
> 
> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>

Applied with a slight change below.

Thanks!

> ---
>  drivers/of/base.c |    9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 7f0e5f7..6d2d45e 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -37,6 +37,7 @@ EXPORT_SYMBOL(of_allnodes);
>  struct device_node *of_chosen;
>  struct device_node *of_aliases;
>  struct device_node *of_stdout;
> +static const char *of_stdout_options;
>  
>  struct kset *of_kset;
>  
> @@ -1844,7 +1845,7 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
>  		if (IS_ENABLED(CONFIG_PPC) && !name)
>  			name = of_get_property(of_aliases, "stdout", NULL);
>  		if (name)
> -			of_stdout = of_find_node_by_path(name);
> +			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
>  	}
>  
>  	if (!of_aliases)
> @@ -1968,9 +1969,13 @@ EXPORT_SYMBOL_GPL(of_prop_next_string);
>   */
>  bool of_console_check(struct device_node *dn, char *name, int index)
>  {
> +	char *console_options;
> +
>  	if (!dn || dn != of_stdout || console_set_on_cmdline)
>  		return false;
> -	return !add_preferred_console(name, index, NULL);
> +
> +	console_options = kstrdup(of_stdout_options, GFP_KERNEL);
> +	return !add_preferred_console(name, index, console_options);

I changed this to simply:
	return !add_preferred_console(name, index,
				      kstrdup(of_stdout_options, GFP_KERNEL));

Not a big deal, just makes for a slightly shorter function.

g.
Peter Hurley Feb. 26, 2015, 11:55 a.m. UTC | #2
On 11/27/2014 12:56 PM, Leif Lindholm wrote:
> Support specifying console options (like with console=ttyXN,<options>)
> by appending them to the stdout-path property after a separating ':'.
> 
> Example:
>         stdout-path = "uart0:115200";

This format breaks DT earlycon because libfdt doesn't recognize ':' as a
path terminator.

It's simple enough to fix this directly in early_init_dt_scan_chosen_serial()
but perhaps it would better to teach fdt_path_offset() to recognize ':'?

Regards,
Peter Hurley

> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
> ---
>  drivers/of/base.c |    9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 7f0e5f7..6d2d45e 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -37,6 +37,7 @@ EXPORT_SYMBOL(of_allnodes);
>  struct device_node *of_chosen;
>  struct device_node *of_aliases;
>  struct device_node *of_stdout;
> +static const char *of_stdout_options;
>  
>  struct kset *of_kset;
>  
> @@ -1844,7 +1845,7 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
>  		if (IS_ENABLED(CONFIG_PPC) && !name)
>  			name = of_get_property(of_aliases, "stdout", NULL);
>  		if (name)
> -			of_stdout = of_find_node_by_path(name);
> +			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
>  	}
>  
>  	if (!of_aliases)
> @@ -1968,9 +1969,13 @@ EXPORT_SYMBOL_GPL(of_prop_next_string);
>   */
>  bool of_console_check(struct device_node *dn, char *name, int index)
>  {
> +	char *console_options;
> +
>  	if (!dn || dn != of_stdout || console_set_on_cmdline)
>  		return false;
> -	return !add_preferred_console(name, index, NULL);
> +
> +	console_options = kstrdup(of_stdout_options, GFP_KERNEL);
> +	return !add_preferred_console(name, index, console_options);
>  }
>  EXPORT_SYMBOL_GPL(of_console_check);
>  
>
Andrew Lunn Feb. 26, 2015, 1:46 p.m. UTC | #3
On Thu, Feb 26, 2015 at 06:55:22AM -0500, Peter Hurley wrote:
> On 11/27/2014 12:56 PM, Leif Lindholm wrote:
> > Support specifying console options (like with console=ttyXN,<options>)
> > by appending them to the stdout-path property after a separating ':'.
> > 
> > Example:
> >         stdout-path = "uart0:115200";
> 
> This format breaks DT earlycon because libfdt doesn't recognize ':' as a
> path terminator.
> 
> It's simple enough to fix this directly in early_init_dt_scan_chosen_serial()
> but perhaps it would better to teach fdt_path_offset() to recognize ':'?

Hi Peter

ePAPR says for stdout-path in Chosen:

A string that specifies the full path to the node representing the
device to be used for boot console output. If the character ":" is
present in the value it terminates the path. The value may be an
alias.

So it is probably wise to implement this properly.

   Andrew
Peter Hurley Feb. 26, 2015, 2:09 p.m. UTC | #4
Hi Andrew,

On 02/26/2015 08:46 AM, Andrew Lunn wrote:
> On Thu, Feb 26, 2015 at 06:55:22AM -0500, Peter Hurley wrote:
>> On 11/27/2014 12:56 PM, Leif Lindholm wrote:
>>> Support specifying console options (like with console=ttyXN,<options>)
>>> by appending them to the stdout-path property after a separating ':'.
>>>
>>> Example:
>>>         stdout-path = "uart0:115200";
>>
>> This format breaks DT earlycon because libfdt doesn't recognize ':' as a
>> path terminator.
>>
>> It's simple enough to fix this directly in early_init_dt_scan_chosen_serial()
>> but perhaps it would better to teach fdt_path_offset() to recognize ':'?
> 
> Hi Peter
> 
> ePAPR says for stdout-path in Chosen:
> 
> A string that specifies the full path to the node representing the
> device to be used for boot console output. If the character ":" is
> present in the value it terminates the path. The value may be an
> alias.
> 
> So it is probably wise to implement this properly.

Sorry if I was unclear. My question was not _whether_ to fix this
for earlycon, but rather _how_.

IOW, is the ':' character accepted as a path terminator for
1. all nodes, so fix this in fdt_path_offset();
2. only chosen nodes;
3. unique to stdout-path, so fix this in early_init_dt_scan_chosen_serial()?

Regards,
Peter Hurley
Andrew Lunn Feb. 26, 2015, 2:44 p.m. UTC | #5
> Sorry if I was unclear. My question was not _whether_ to fix this
> for earlycon, but rather _how_.
> 
> IOW, is the ':' character accepted as a path terminator for
> 1. all nodes, so fix this in fdt_path_offset();
> 2. only chosen nodes;
> 3. unique to stdout-path, so fix this in early_init_dt_scan_chosen_serial()?

Ah, sorry.

The ':' character is accepted as a path terminator for stdout-path and
stdin-path within chosen node. It does not appear to be mentioned
anywhere else in the standard.

	 Andrew
diff mbox

Patch

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 7f0e5f7..6d2d45e 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -37,6 +37,7 @@  EXPORT_SYMBOL(of_allnodes);
 struct device_node *of_chosen;
 struct device_node *of_aliases;
 struct device_node *of_stdout;
+static const char *of_stdout_options;
 
 struct kset *of_kset;
 
@@ -1844,7 +1845,7 @@  void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
 		if (IS_ENABLED(CONFIG_PPC) && !name)
 			name = of_get_property(of_aliases, "stdout", NULL);
 		if (name)
-			of_stdout = of_find_node_by_path(name);
+			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
 	}
 
 	if (!of_aliases)
@@ -1968,9 +1969,13 @@  EXPORT_SYMBOL_GPL(of_prop_next_string);
  */
 bool of_console_check(struct device_node *dn, char *name, int index)
 {
+	char *console_options;
+
 	if (!dn || dn != of_stdout || console_set_on_cmdline)
 		return false;
-	return !add_preferred_console(name, index, NULL);
+
+	console_options = kstrdup(of_stdout_options, GFP_KERNEL);
+	return !add_preferred_console(name, index, console_options);
 }
 EXPORT_SYMBOL_GPL(of_console_check);