[PATCH v2 01/13] drm/mediatek: add refcount for DPI power on/off
From: CK Hu <hidden>
Date: 2018-09-05 09:30:49
Also in:
dri-devel, linux-mediatek, lkml
Hi, Bibby: This looks reasonable, but why MT8173 doesn't need this patch? So describe more about why MT7623 need this patch. If this is caused by latest DRM core flow change, I think we should treat this patch independent with MT7623. Regards, CK On Wed, 2018-09-05 at 16:31 +0800, Bibby Hsieh wrote:
quoted hunk ↗ jump to hunk
From: chunhui dai <redacted> add refcount for DPI power on/off to protect the flow Signed-off-by: chunhui dai <redacted> --- drivers/gpu/drm/mediatek/mtk_dpi.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index 6c0ea39d5739..d9373e67d328 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c@@ -77,6 +77,7 @@ struct mtk_dpi { enum mtk_dpi_out_bit_num bit_num; enum mtk_dpi_out_channel_swap channel_swap; bool power_sta; + int refcount; u8 power_ctl; };@@ -369,6 +370,12 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi, static void mtk_dpi_power_off(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) { + if (WARN_ON(dpi->refcount == 0)) + return; + + if (--dpi->refcount != 0) + return; + dpi->power_ctl &= ~pctl; if ((dpi->power_ctl & DPI_POWER_START) ||@@ -388,14 +395,17 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) { int ret; + if (++dpi->refcount != 1) + return 0; + dpi->power_ctl |= pctl; if (!(dpi->power_ctl & DPI_POWER_START) && !(dpi->power_ctl & DPI_POWER_ENABLE)) - return 0; + goto err_refcount; if (dpi->power_sta) - return 0; + goto err_refcount; ret = clk_prepare_enable(dpi->engine_clk); if (ret) {@@ -417,6 +427,8 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) clk_disable_unprepare(dpi->engine_clk); err_eng: dpi->power_ctl &= ~pctl; +err_refcount: + dpi->refcount--; return ret; }