[U-Boot] [PATCH 5/7] lcd: Fix fb offset calculation for bpix == 16 in BMP display

[Simon Glass]

Hi Nikita,

On Thu, Oct 4, 2012 at 1:48 AM, Nikita Kiryanov <nikita at compulab.co.il> wrote:
> Hi Simon,
>
>
> On 09/29/2012 03:11 AM, Simon Glass wrote:
>>
>> From: Tom Wai-Hong Tam <waihong at chromium.org>
>>
>> For bpix == 16, each pixel is 2-byte. fb offset should shift more x bytes.
>>
>> Signed-off-by: Tom Wai-Hong Tam <waihong at chromium.org>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>   common/lcd.c |    6 ++++--
>>   1 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/common/lcd.c b/common/lcd.c
>> index 7c6cb09..004a6be 100644
>> --- a/common/lcd.c
>> +++ b/common/lcd.c
>> @@ -775,8 +775,10 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>>                 height = panel_info.vl_row - y;
>>
>>         bmap = (uchar *)bmp + le32_to_cpu(bmp->header.data_offset);
>> -       fb   = (uchar *) (lcd_base +
>> -               (y + height - 1) * lcd_line_length + x * bpix / 8);
>> +       fb   = (uchar *) (lcd_base + (y + height - 1) * lcd_line_length +
>> x);
>> +       /* additional fb shift for bpix == 16 since each pixel is 2-byte
>> */
>> +       if (bpix == 16)
>> +               fb += x;
>>
>
> Why is this change necessary? if bpix == 16 then x * bpix / 8 == 2 * x
> anyway.

Yes I agree, I can't see what the difference might me. Tom, do you
have any idea on this please?

Regards,
Simon

>
>
>>         switch (bmp_bpix) {
>>         case 1: /* pass through */
>>
>