This is a note to let you know that I've just added the patch titled drm/ingenic: Use the highest possible DMA burst size to the 5.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-ingenic-use-the-highest-possible-dma-burst-size.patch and it can be found in the queue-5.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f0dce5c4fdaf9e98dd2755ffb1363822854b6287 Mon Sep 17 00:00:00 2001 From: Paul Cercueil <paul@xxxxxxxxxxxxxxx> Date: Sun, 3 Jul 2022 00:07:27 +0100 Subject: drm/ingenic: Use the highest possible DMA burst size From: Paul Cercueil <paul@xxxxxxxxxxxxxxx> commit f0dce5c4fdaf9e98dd2755ffb1363822854b6287 upstream. 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@xxxxxxxxxxxxxxx> Fixes: 90b86fcc47b4 ("DRM: Add KMS driver for the Ingenic JZ47xx SoCs") Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20220702230727.66704-1-paul@xxxxxxxxxxxxxxx Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> Tested-by: Christophe Branchereau <cbranchereau@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 10 ++++++++-- drivers/gpu/drm/ingenic/ingenic-drm.h | 3 +++ 2 files changed, 11 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -69,6 +69,7 @@ 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; @@ -318,8 +319,9 @@ static void ingenic_drm_crtc_update_timi 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 @@ -1518,6 +1520,7 @@ static const struct jz_soc_info jz4740_s .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 */ @@ -1529,6 +1532,7 @@ static const struct jz_soc_info jz4725b_ .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, @@ -1541,6 +1545,7 @@ static const struct jz_soc_info jz4770_s .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, @@ -1555,6 +1560,7 @@ static const struct jz_soc_info jz4780_s .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, --- a/drivers/gpu/drm/ingenic/ingenic-drm.h +++ b/drivers/gpu/drm/ingenic/ingenic-drm.h @@ -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) Patches currently in stable-queue which might be from paul@xxxxxxxxxxxxxxx are queue-5.19/drm-ingenic-use-the-highest-possible-dma-burst-size.patch