Re: [PATCH v4 10/10] drm/ingenic: add some jz4780 specific features

Hi,

Le lun., sept. 27 2021 at 18:44:28 +0200, H. Nikolaus Schaller hns@goldelico.com a écrit :

From: Paul Boddie paul@boddie.org.uk

The jz4780 has some features which need initialization according to the vendor kernel.

Signed-off-by: Paul Boddie paul@boddie.org.uk Signed-off-by: H. Nikolaus Schaller hns@goldelico.com

---

drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 39 +++++++++++++++++++++++ 1 file changed, 39 insertions(+)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index e2df4b085905..605549b316b5 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -66,6 +66,10 @@ struct jz_soc_info { bool needs_dev_clk; bool has_osd; bool map_noncoherent;

• bool has_alpha;
• bool has_pcfg;
• bool has_recover;
• bool has_rgbc; bool use_extended_hwdesc; unsigned int max_width, max_height; const u32 *formats_f0, *formats_f1;

@@ -732,6 +736,9 @@ static void ingenic_drm_encoder_atomic_mode_set(struct drm_encoder *encoder, | JZ_LCD_CFG_SPL_DISABLE | JZ_LCD_CFG_REV_DISABLE; }

• if (priv->soc_info->has_recover)

• cfg |= JZ_LCD_CFG_RECOVER_FIFO_UNDERRUN;
  

Did you actually test this? I know that in theory it sounds like something we'd want, but unless there is a proven use for it, it's better to keep it disabled.

• /* set use of the 8-word descriptor and OSD foreground usage. */ if (priv->soc_info->use_extended_hwdesc) cfg |= JZ_LCD_CFG_DESCRIPTOR_8;

@@ -1321,6 +1328,25 @@ static int ingenic_drm_bind(struct device *dev, bool has_components) if (soc_info->has_osd) regmap_set_bits(priv->map, JZ_REG_LCD_OSDC, JZ_LCD_OSDC_OSDEN);

• if (soc_info->has_alpha)

• regmap_set_bits(priv->map, JZ_REG_LCD_OSDC, JZ_LCD_OSDC_ALPHAEN);
  

I remember you saying that OSD mode was not yet working on the JZ4780. So I can't see how you could have tested this.

• /* Magic values from the vendor kernel for the priority thresholds.

*/

• if (soc_info->has_pcfg)

• regmap_write(priv->map, JZ_REG_LCD_PCFG,
  

• 	     JZ_LCD_PCFG_PRI_MODE |
  

• 	     JZ_LCD_PCFG_HP_BST_16 |
  

• 	     (511 << JZ_LCD_PCFG_THRESHOLD2_OFFSET) |
  

• 	     (400 << JZ_LCD_PCFG_THRESHOLD1_OFFSET) |
  

• 	     (256 << JZ_LCD_PCFG_THRESHOLD0_OFFSET));
  

Unless you add a big comment that explains what these values do and why we do want them, I don't want magic values in here. The fact that the kernel vendor sets this doesn't mean it's needed and/or wanted.

• /* RGB output control may be superfluous. */
• if (soc_info->has_rgbc)

• regmap_write(priv->map, JZ_REG_LCD_RGBC,
  

• 	     JZ_LCD_RGBC_RGB_FORMAT_ENABLE |
  

• 	     JZ_LCD_RGBC_ODD_RGB |
  

• 	     JZ_LCD_RGBC_EVEN_RGB);
  

ingenic-drm only supports RGB output right now, so I guess the RGB_FORMAT_ENABLE bit needs to be set in patch [2/10], otherwise patch [2/10] cannot state that it adds support for the JZ4780, if it doesn't actually work.

The other two bits can be dropped, they are already set in ingenic_drm_encoder_atomic_mode_set().

• mutex_init(&priv->clk_mutex); priv->clock_nb.notifier_call = ingenic_drm_update_pixclk;

@@ -1484,6 +1510,9 @@ static const struct jz_soc_info jz4740_soc_info = { .needs_dev_clk = true, .has_osd = false, .map_noncoherent = false,

• .has_pcfg = false,
• .has_recover = false,
• .has_rgbc = false, .max_width = 800, .max_height = 600, .formats_f1 = jz4740_formats,

@@ -1496,6 +1525,9 @@ static const struct jz_soc_info jz4725b_soc_info = { .needs_dev_clk = false, .has_osd = true, .map_noncoherent = false,

• .has_pcfg = false,
• .has_recover = false,
• .has_rgbc = false,

This is wrong, the JZ4725B and JZ4770 SoCs both have the RGBC register and the RECOVER bit.

Cheers, -Paul

.max_width = 800, .max_height = 600, .formats_f1 = jz4725b_formats_f1, @@ -1509,6 +1541,9 @@ static const struct jz_soc_info jz4770_soc_info = { .needs_dev_clk = false, .has_osd = true, .map_noncoherent = true,

• .has_pcfg = false,
• .has_recover = false,
• .has_rgbc = false, .max_width = 1280, .max_height = 720, .formats_f1 = jz4770_formats_f1,

@@ -1521,6 +1556,10 @@ static const struct jz_soc_info jz4770_soc_info = { static const struct jz_soc_info jz4780_soc_info = { .needs_dev_clk = true, .has_osd = true,

• .has_alpha = true,
• .has_pcfg = true,
• .has_recover = true,
• .has_rgbc = true, .use_extended_hwdesc = true, .max_width = 4096, .max_height = 2048,

-- 2.31.1