[U-Boot] lcd: fix console address is not initialized

This commit 904672e (lcd: refactor lcd console stuff into its
own file), which cause lcd console address is not initialized.

This patch split lcd console address initialize and lcd logo
display into two functions.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
---

 common/lcd.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Hi Bo,

On 01/21/2015 06:37 AM, Bo Shen wrote:
> This commit 904672e (lcd: refactor lcd console stuff into its
> own file), which cause lcd console address is not initialized.

Based on your fix, I'm certain that the bug was introduced in a
previous patch, perhaps 140beb9 (lcd: expand console api).

Also, can you provide a more detailed explanation of when this
happens and how?

>
> This patch split lcd console address initialize and lcd logo
> display into two functions.
>
> Signed-off-by: Bo Shen <voice.shen@atmel.com>
> ---
>
>   common/lcd.c | 11 ++++++++---
>   1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/common/lcd.c b/common/lcd.c
> index cc34b8a..f435e2a 100644
> --- a/common/lcd.c
> +++ b/common/lcd.c
> @@ -82,7 +82,8 @@ DECLARE_GLOBAL_DATA_PTR;
>
>   static int lcd_init(void *lcdbase);
>
> -static void *lcd_logo(void);
> +static void lcd_logo(void);
> +static void *lcd_console_address(void);
>
>   static void lcd_setfgcolor(int color);
>   static void lcd_setbgcolor(int color);
> @@ -268,7 +269,8 @@ void lcd_clear(void)
>   	console_rows = panel_info.vl_row / VIDEO_FONT_HEIGHT;
>   #endif
>   	console_cols = panel_info.vl_col / VIDEO_FONT_WIDTH;
> -	lcd_init_console(lcd_logo(), console_rows, console_cols);
> +	lcd_init_console(lcd_console_address(), console_rows, console_cols);
> +	lcd_logo();
>   	lcd_sync();
>   }
>
> @@ -849,7 +851,7 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>   }
>   #endif
>
> -static void *lcd_logo(void)
> +static void lcd_logo(void)
>   {
>   #ifdef CONFIG_SPLASH_SCREEN
>   	char *s;
> @@ -879,7 +881,10 @@ static void *lcd_logo(void)
>   	lcd_set_row(LCD_INFO_Y / VIDEO_FONT_HEIGHT);
>   	lcd_show_board_info();
>   #endif /* CONFIG_LCD_INFO */
> +}
>
> +static void *lcd_console_address(void)
> +{
>   #if defined(CONFIG_LCD_LOGO) && !defined(CONFIG_LCD_INFO_BELOW_LOGO)
>   	return (void *)((ulong)lcd_base + BMP_LOGO_HEIGHT * lcd_line_length);
>   #else
>

I would like to see some mention of why it's ok to redefine the console
address in such a way. At first glance it looks like there is a slight change of
behavior (the value no longer depends on whether splash image was loaded
or not), but it seems to be ok if you go over the various cases. The only
instance where I see the difference could manifest itself is if lcd console
would start writing to the frame buffer while the splash screen is still on,
but that doesn't look good regardless of where the console starts, so I'm ok
with that.

Hi Nikita Kiryanov,

On 01/22/2015 09:10 PM, Nikita Kiryanov wrote:
> Hi Bo,
>
> On 01/21/2015 06:37 AM, Bo Shen wrote:
>> This commit 904672e (lcd: refactor lcd console stuff into its
>> own file), which cause lcd console address is not initialized.
>
> Based on your fix, I'm certain that the bug was introduced in a
> previous patch, perhaps 140beb9 (lcd: expand console api).
>
> Also, can you provide a more detailed explanation of when this
> happens and how?

It will cause the system hang.

Before this patch, lcd_logo -> lcd_show_board_info (CONFIG_LCD_INFO) -> 
.. -> lcd_drawchars. It has the following lines:
--->8---
dest = (uchar *)(lcd_base + y * lcd_line_length + x * NBITS(LCD_BPP)/8);
---8<---

while with the patch,
--->8---
dest = (uchar *)(lcd_console_address +
                          y * lcd_line_length + x * NBITS(LCD_BPP) / 8);
---8<---

As the lcd_console_address is initialized after lcd_logo return, so the 
lcd_console_address is not initialized, it is 0. When try to write to 
address 0, the system hang.

>>
>> This patch split lcd console address initialize and lcd logo
>> display into two functions.
>>
>> Signed-off-by: Bo Shen <voice.shen@atmel.com>
>> ---
>>
>>   common/lcd.c | 11 ++++++++---
>>   1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/common/lcd.c b/common/lcd.c
>> index cc34b8a..f435e2a 100644
>> --- a/common/lcd.c
>> +++ b/common/lcd.c
>> @@ -82,7 +82,8 @@ DECLARE_GLOBAL_DATA_PTR;
>>
>>   static int lcd_init(void *lcdbase);
>>
>> -static void *lcd_logo(void);
>> +static void lcd_logo(void);
>> +static void *lcd_console_address(void);
>>
>>   static void lcd_setfgcolor(int color);
>>   static void lcd_setbgcolor(int color);
>> @@ -268,7 +269,8 @@ void lcd_clear(void)
>>       console_rows = panel_info.vl_row / VIDEO_FONT_HEIGHT;
>>   #endif
>>       console_cols = panel_info.vl_col / VIDEO_FONT_WIDTH;
>> -    lcd_init_console(lcd_logo(), console_rows, console_cols);
>> +    lcd_init_console(lcd_console_address(), console_rows, console_cols);
>> +    lcd_logo();
>>       lcd_sync();
>>   }
>>
>> @@ -849,7 +851,7 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>>   }
>>   #endif
>>
>> -static void *lcd_logo(void)
>> +static void lcd_logo(void)
>>   {
>>   #ifdef CONFIG_SPLASH_SCREEN
>>       char *s;
>> @@ -879,7 +881,10 @@ static void *lcd_logo(void)
>>       lcd_set_row(LCD_INFO_Y / VIDEO_FONT_HEIGHT);
>>       lcd_show_board_info();
>>   #endif /* CONFIG_LCD_INFO */
>> +}
>>
>> +static void *lcd_console_address(void)
>> +{
>>   #if defined(CONFIG_LCD_LOGO) && !defined(CONFIG_LCD_INFO_BELOW_LOGO)
>>       return (void *)((ulong)lcd_base + BMP_LOGO_HEIGHT *
>> lcd_line_length);
>>   #else
>>
>
> I would like to see some mention of why it's ok to redefine the console
> address in such a way. At first glance it looks like there is a slight
> change of
> behavior (the value no longer depends on whether splash image was loaded
> or not), but it seems to be ok if you go over the various cases. The only
> instance where I see the difference could manifest itself is if lcd console
> would start writing to the frame buffer while the splash screen is still
> on,
> but that doesn't look good regardless of where the console starts, so
> I'm ok
> with that.
>

Thanks for reminder this, I will check whether this will break the 
splash screen.

Best Regards,
Bo Shen