diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.19.8/1769-drm-amd-display-Add-switch-for-Fractional-PWM-on-or-.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.19.8/1769-drm-amd-display-Add-switch-for-Fractional-PWM-on-or-.patch | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.19.8/1769-drm-amd-display-Add-switch-for-Fractional-PWM-on-or-.patch b/common/recipes-kernel/linux/linux-yocto-4.19.8/1769-drm-amd-display-Add-switch-for-Fractional-PWM-on-or-.patch new file mode 100644 index 00000000..d9e0ec50 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.19.8/1769-drm-amd-display-Add-switch-for-Fractional-PWM-on-or-.patch @@ -0,0 +1,76 @@ +From a6dcfa6147cf37b207ea8b1185637eafffcd836f Mon Sep 17 00:00:00 2001 +From: Anthony Koo <Anthony.Koo@amd.com> +Date: Thu, 28 Mar 2019 12:39:48 -0400 +Subject: [PATCH 1769/2940] drm/amd/display: Add switch for Fractional PWM on + or off + +[Why] +Some LED Driver might not like Fractional PWM especially at extreme +ranges near 0% or 100%. +For example, backlight flashing could be observed. +We want a way to switch fractional PWM on/off either for debug, or +possibly production. + +[How] +Add DC code that can send new FW command to enable/disable +fractional PWM. + +Signed-off-by: Anthony Koo <Anthony.Koo@amd.com> +Reviewed-by: Aric Cyr <Aric.Cyr@amd.com> +Acked-by: Leo Li <sunpeng.li@amd.com> +--- + drivers/gpu/drm/amd/display/dc/dc.h | 1 + + drivers/gpu/drm/amd/display/dc/dce/dce_abm.c | 18 ++++++++++++++++++ + 2 files changed, 19 insertions(+) + +diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h +index facc830fa428..8a645ec8e293 100644 +--- a/drivers/gpu/drm/amd/display/dc/dc.h ++++ b/drivers/gpu/drm/amd/display/dc/dc.h +@@ -186,6 +186,7 @@ struct dc_config { + bool disable_disp_pll_sharing; + bool fbc_support; + bool optimize_edp_link_rate; ++ bool disable_fractional_pwm; + bool allow_seamless_boot_optimization; + }; + +diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c +index da96229db53a..855360b1414f 100644 +--- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c ++++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c +@@ -50,6 +50,7 @@ + #define MCP_ABM_LEVEL_SET 0x65 + #define MCP_ABM_PIPE_SET 0x66 + #define MCP_BL_SET 0x67 ++#define MCP_BL_SET_PWM_FRAC 0x6A /* Enable or disable Fractional PWM */ + + #define MCP_DISABLE_ABM_IMMEDIATELY 255 + +@@ -390,6 +391,23 @@ static bool dce_abm_init_backlight(struct abm *abm) + REG_UPDATE(BL_PWM_GRP1_REG_LOCK, + BL_PWM_GRP1_REG_LOCK, 0); + ++ /* Wait until microcontroller is ready to process interrupt */ ++ REG_WAIT(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, 0, 100, 800); ++ ++ /* Set PWM fractional enable/disable */ ++ value = (abm->ctx->dc->config.disable_fractional_pwm == false) ? 1 : 0; ++ REG_WRITE(MASTER_COMM_DATA_REG1, value); ++ ++ /* Set command to enable or disable fractional PWM microcontroller */ ++ REG_UPDATE(MASTER_COMM_CMD_REG, MASTER_COMM_CMD_REG_BYTE0, ++ MCP_BL_SET_PWM_FRAC); ++ ++ /* Notify microcontroller of new command */ ++ REG_UPDATE(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, 1); ++ ++ /* Ensure command has been executed before continuing */ ++ REG_WAIT(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, 0, 100, 800); ++ + return true; + } + +-- +2.17.1 + |