[PATCH v2] drm/ast: Add Atomic gamma lut support for aspeed

Jocelyn Falempe jfalempe at redhat.com
Fri Sep 30 06:52:19 UTC 2022


On 29/09/2022 17:27, Thomas Zimmermann wrote:
> Hi
> 
> Am 29.09.22 um 15:20 schrieb Jocelyn Falempe:
>> The current ast driver only supports legacy gamma interface.
>> This also fixes a Gnome3/Wayland error which incorrectly adds
>> gamma to atomic commit:
>> "Page flip discarded: CRTC property (GAMMA_LUT) not found"
>>
>> I only tested remotely, so I wasn't able to check that it had
>> an effect on the VGA output. But when activating "Night Light"
>> in Gnome, ast_crtc_load_lut() is called.
>>
>> v2: use the same functions as mgag200.
>>      handle 16bits color mode.
>>
>> Signed-off-by: Jocelyn Falempe <jfalempe at redhat.com>
> 
> That works well on my AST2300 test system. The one thing missing is the 
> CRTC's atomic_check code. See
> 
> 
> https://cgit.freedesktop.org/drm/drm-tip/tree/drivers/gpu/drm/mgag200/mgag200_mode.c#n597

Thanks for the test and confirmation that it's working.
I'm adding the check and will send a v3 soon.

Best regards,

-- 

Jocelyn

> 
> for what to do. With this test implemented, you can add
> 
> Tested-by: Thomas Zimmermann <tzimmermann at suse.de>
> Reviewed-by: Thomas Zimmermann <tzimmermann at suse.de>
> 
> to the patch.
> 
> Best regards
> Thomas
> 
>> ---
>>   drivers/gpu/drm/ast/ast_mode.c | 94 ++++++++++++++++++++++++++++------
>>   1 file changed, 77 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ast/ast_mode.c 
>> b/drivers/gpu/drm/ast/ast_mode.c
>> index 214b10178454..06ea13c3a9b4 100644
>> --- a/drivers/gpu/drm/ast/ast_mode.c
>> +++ b/drivers/gpu/drm/ast/ast_mode.c
>> @@ -49,6 +49,8 @@
>>   #include "ast_drv.h"
>>   #include "ast_tables.h"
>> +#define AST_LUT_SIZE 256
>> +
>>   static inline void ast_load_palette_index(struct ast_private *ast,
>>                        u8 index, u8 red, u8 green,
>>                        u8 blue)
>> @@ -63,20 +65,71 @@ static inline void ast_load_palette_index(struct 
>> ast_private *ast,
>>       ast_io_read8(ast, AST_IO_SEQ_PORT);
>>   }
>> -static void ast_crtc_load_lut(struct ast_private *ast, struct 
>> drm_crtc *crtc)
>> +static void ast_crtc_set_gamma_linear(struct ast_private *ast,
>> +                      const struct drm_format_info *format)
>>   {
>> -    u16 *r, *g, *b;
>>       int i;
>> -    if (!crtc->enabled)
>> -        return;
>> +    switch (format->format) {
>> +    case DRM_FORMAT_RGB565:
>> +        /* Use better interpolation, to take 32 values from 0 to 255 */
>> +        for (i = 0; i < AST_LUT_SIZE / 8; i++)
>> +            ast_load_palette_index(ast,
>> +                           i,
>> +                           i * 8 + i / 4,
>> +                           i * 4 + i / 16,
>> +                           i * 8 + i / 4);
>> +        /* Green has one more bit, so add padding with 0 for red and 
>> blue. */
>> +        for (i = AST_LUT_SIZE / 8; i < AST_LUT_SIZE / 4; i++)
>> +            ast_load_palette_index(ast, i, 0, i * 4 + i / 16, 0);
>> +        break;
>> +    case DRM_FORMAT_C8: /* In this case, gamma table is used as color 
>> palette */
>> +    case DRM_FORMAT_RGB888:
>> +    case DRM_FORMAT_XRGB8888:
>> +        for (i = 0; i < AST_LUT_SIZE; i++)
>> +            ast_load_palette_index(ast, i, i, i, i);
>> +        break;
>> +    default:
>> +        drm_warn_once(&ast->base, "Unsupported format %p4cc for gamma 
>> correction\n",
>> +                  &format->format);
>> +        break;
>> +    }
>> +}
>> -    r = crtc->gamma_store;
>> -    g = r + crtc->gamma_size;
>> -    b = g + crtc->gamma_size;
>> +static void ast_crtc_set_gamma(struct ast_private *ast,
>> +                   const struct drm_format_info *format,
>> +                   struct drm_color_lut *lut)
>> +{
>> +    int i;
>> -    for (i = 0; i < 256; i++)
>> -        ast_load_palette_index(ast, i, *r++ >> 8, *g++ >> 8, *b++ >> 8);
>> +    switch (format->format) {
>> +    case DRM_FORMAT_RGB565:
>> +        /* Use better interpolation, to take 32 values from lut[0] to 
>> lut[255] */
>> +        for (i = 0; i < AST_LUT_SIZE / 8; i++)
>> +            ast_load_palette_index(ast,
>> +                           i,
>> +                           lut[i * 8 + i / 4].red >> 8,
>> +                           lut[i * 4 + i / 16].green >> 8,
>> +                           lut[i * 8 + i / 4].blue >> 8);
>> +        /* Green has one more bit, so add padding with 0 for red and 
>> blue. */
>> +        for (i = AST_LUT_SIZE / 8; i < AST_LUT_SIZE / 4; i++)
>> +            ast_load_palette_index(ast, i, 0, lut[i * 4 + i / 
>> 16].green >> 8, 0);
>> +        break;
>> +    case DRM_FORMAT_C8: /* In this case, gamma table is used as color 
>> palette */
>> +    case DRM_FORMAT_RGB888:
>> +    case DRM_FORMAT_XRGB8888:
>> +        for (i = 0; i < AST_LUT_SIZE; i++)
>> +            ast_load_palette_index(ast,
>> +                           i,
>> +                           lut[i].red >> 8,
>> +                           lut[i].green >> 8,
>> +                           lut[i].blue >> 8);
>> +        break;
>> +    default:
>> +        drm_warn_once(&ast->base, "Unsupported format %p4cc for gamma 
>> correction\n",
>> +                  &format->format);
>> +        break;
>> +    }
>>   }
>>   static bool ast_get_vbios_mode_info(const struct drm_format_info 
>> *format,
>> @@ -1018,9 +1071,11 @@ static void ast_crtc_dpms(struct drm_crtc 
>> *crtc, int mode)
>>               ast_set_color_reg(ast, format);
>>               ast_set_vbios_color_reg(ast, format, vbios_mode_info);
>> +            if (crtc->state->gamma_lut)
>> +                ast_crtc_set_gamma(ast, format, 
>> crtc->state->gamma_lut->data);
>> +            else
>> +                ast_crtc_set_gamma_linear(ast, format);
>>           }
>> -
>> -        ast_crtc_load_lut(ast, crtc);
>>           break;
>>       case DRM_MODE_DPMS_STANDBY:
>>       case DRM_MODE_DPMS_SUSPEND:
>> @@ -1158,20 +1213,23 @@ ast_crtc_helper_atomic_flush(struct drm_crtc 
>> *crtc,
>>   {
>>       struct drm_crtc_state *crtc_state = 
>> drm_atomic_get_new_crtc_state(state,
>>                                         crtc);
>> -    struct drm_crtc_state *old_crtc_state = 
>> drm_atomic_get_old_crtc_state(state,
>> -                                          crtc);
>>       struct drm_device *dev = crtc->dev;
>>       struct ast_private *ast = to_ast_private(dev);
>>       struct ast_crtc_state *ast_crtc_state = 
>> to_ast_crtc_state(crtc_state);
>> -    struct ast_crtc_state *old_ast_crtc_state = 
>> to_ast_crtc_state(old_crtc_state);
>>       struct ast_vbios_mode_info *vbios_mode_info = 
>> &ast_crtc_state->vbios_mode_info;
>>       /*
>>        * The gamma LUT has to be reloaded after changing the primary
>>        * plane's color format.
>>        */
>> -    if (old_ast_crtc_state->format != ast_crtc_state->format)
>> -        ast_crtc_load_lut(ast, crtc);
>> +    if (crtc_state->enable && crtc_state->color_mgmt_changed) {
>> +        if (crtc_state->gamma_lut)
>> +            ast_crtc_set_gamma(ast,
>> +                       ast_crtc_state->format,
>> +                       crtc_state->gamma_lut->data);
>> +        else
>> +            ast_crtc_set_gamma_linear(ast, ast_crtc_state->format);
>> +    }
>>       //Set Aspeed Display-Port
>>       if (ast->tx_chip_types & AST_TX_ASTDP_BIT)
>> @@ -1309,7 +1367,9 @@ static int ast_crtc_init(struct drm_device *dev)
>>       if (ret)
>>           return ret;
>> -    drm_mode_crtc_set_gamma_size(crtc, 256);
>> +    drm_mode_crtc_set_gamma_size(crtc, AST_LUT_SIZE);
>> +    drm_crtc_enable_color_mgmt(crtc, 0, false, AST_LUT_SIZE);
>> +
>>       drm_crtc_helper_add(crtc, &ast_crtc_helper_funcs);
>>       return 0;
> 



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