Unverified Commit f0dce5c4 authored by Paul Cercueil's avatar Paul Cercueil
Browse files

drm/ingenic: Use the highest possible DMA burst size 



Until now, when running at the maximum resolution of 1280x720 at 32bpp
on the JZ4770 SoC the output was garbled, the X/Y position of the
top-left corner of the framebuffer warping to a random position with
the whole image being offset accordingly, every time a new frame was
being submitted.

This problem can be eliminated by using a bigger burst size for the DMA.

Set in each soc_info structure the maximum burst size supported by the
corresponding SoC, and use it in the driver.

Set the new value using regmap_update_bits() instead of
regmap_set_bits(), since we do want to override the old value of the
burst size. (Note that regmap_set_bits() wasn't really valid before for
the same reason, but it never seemed to be a problem).

Cc: <stable@vger.kernel.org>
Fixes: 90b86fcc ("DRM: Add KMS driver for the Ingenic JZ47xx SoCs")
Signed-off-by: default avatarPaul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20220702230727.66704-1-paul@crapouillou.net


Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Tested-by: default avatarChristophe Branchereau <cbranchereau@gmail.com>
parent a6cc3c72

drivers/gpu/drm/ingenic/ingenic-drm-drv.c

+8 −2
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ struct jz_soc_info { 
	bool map_noncoherent;

	bool use_extended_hwdesc;

	bool plane_f0_not_working;

	u32 max_burst;

	unsigned int max_width, max_height;

	const u32 *formats_f0, *formats_f1;

	unsigned int num_formats_f0, num_formats_f1;
@@ -319,8 +320,9 @@ static void ingenic_drm_crtc_update_timings(struct ingenic_drm *priv, 
		regmap_write(priv->map, JZ_REG_LCD_REV, mode->htotal << 16);

	}



	regmap_set_bits(priv->map, JZ_REG_LCD_CTRL,

			JZ_LCD_CTRL_OFUP | JZ_LCD_CTRL_BURST_16);

	regmap_update_bits(priv->map, JZ_REG_LCD_CTRL,

			   JZ_LCD_CTRL_OFUP | JZ_LCD_CTRL_BURST_MASK,

			   JZ_LCD_CTRL_OFUP | priv->soc_info->max_burst);



	/*

	 * IPU restart - specify how much time the LCDC will wait before
@@ -1519,6 +1521,7 @@ static const struct jz_soc_info jz4740_soc_info = { 
	.map_noncoherent = false,

	.max_width = 800,

	.max_height = 600,

	.max_burst = JZ_LCD_CTRL_BURST_16,

	.formats_f1 = jz4740_formats,

	.num_formats_f1 = ARRAY_SIZE(jz4740_formats),

	/* JZ4740 has only one plane */
@@ -1530,6 +1533,7 @@ static const struct jz_soc_info jz4725b_soc_info = { 
	.map_noncoherent = false,

	.max_width = 800,

	.max_height = 600,

	.max_burst = JZ_LCD_CTRL_BURST_16,

	.formats_f1 = jz4725b_formats_f1,

	.num_formats_f1 = ARRAY_SIZE(jz4725b_formats_f1),

	.formats_f0 = jz4725b_formats_f0,
@@ -1542,6 +1546,7 @@ static const struct jz_soc_info jz4770_soc_info = { 
	.map_noncoherent = true,

	.max_width = 1280,

	.max_height = 720,

	.max_burst = JZ_LCD_CTRL_BURST_64,

	.formats_f1 = jz4770_formats_f1,

	.num_formats_f1 = ARRAY_SIZE(jz4770_formats_f1),

	.formats_f0 = jz4770_formats_f0,
@@ -1556,6 +1561,7 @@ static const struct jz_soc_info jz4780_soc_info = { 
	.plane_f0_not_working = true,	/* REVISIT */

	.max_width = 4096,

	.max_height = 2048,

	.max_burst = JZ_LCD_CTRL_BURST_64,

	.formats_f1 = jz4770_formats_f1,

	.num_formats_f1 = ARRAY_SIZE(jz4770_formats_f1),

	.formats_f0 = jz4770_formats_f0,

drivers/gpu/drm/ingenic/ingenic-drm.h

+3 −0
Original line number Diff line number Diff line
@@ -106,6 +106,9 @@ 
#define JZ_LCD_CTRL_BURST_4			(0x0 << 28)

#define JZ_LCD_CTRL_BURST_8			(0x1 << 28)

#define JZ_LCD_CTRL_BURST_16			(0x2 << 28)

#define JZ_LCD_CTRL_BURST_32			(0x3 << 28)

#define JZ_LCD_CTRL_BURST_64			(0x4 << 28)

#define JZ_LCD_CTRL_BURST_MASK			(0x7 << 28)

#define JZ_LCD_CTRL_RGB555			BIT(27)

#define JZ_LCD_CTRL_OFUP			BIT(26)

#define JZ_LCD_CTRL_FRC_GRAYSCALE_16		(0x0 << 24)