From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bibby Hsieh Subject: [PATCH v2 01/13] drm/mediatek: add refcount for DPI power on/off Date: Wed, 5 Sep 2018 16:31:34 +0800 Message-ID: <20180905083146.14727-2-bibby.hsieh@mediatek.com> References: <20180905083146.14727-1-bibby.hsieh@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20180905083146.14727-1-bibby.hsieh@mediatek.com> Sender: linux-kernel-owner@vger.kernel.org To: David Airlie , Matthias Brugger , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org Cc: Yingjoe Chen , Cawa Cheng , Daniel Kurtz , Bibby Hsieh , Philipp Zabel , YT Shen , Thierry Reding , CK Hu , Mao Huang , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sascha Hauer , chunhui dai List-Id: linux-mediatek@lists.infradead.org From: chunhui dai add refcount for DPI power on/off to protect the flow Signed-off-by: chunhui dai --- 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; } -- 2.12.5.2.gbdf23ab