From cbda8e6de54f8a0f194e990f53e1cfad642af1be Mon Sep 17 00:00:00 2001 From: Chris Miller Date: Wed, 26 Jun 2019 10:40:30 +0100 Subject: [PATCH] drm: vc4_dsi: Fix DMA channel and memory leak in vc4 (#3012) Signed-off-by: Chris G Miller --- drivers/gpu/drm/vc4/vc4_dsi.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -1485,9 +1485,11 @@ static int vc4_dsi_bind(struct device *d /* DSI1 has a broken AXI slave that doesn't respond to writes * from the ARM. It does handle writes from the DMA engine, * so set up a channel for talking to it. + * Where possible managed resource providers are used, but the DMA channel + * must - if acquired - be explicitly released prior to taking an error exit path. */ if (dsi->port == 1) { - dsi->reg_dma_mem = dma_alloc_coherent(dev, 4, + dsi->reg_dma_mem = dmam_alloc_coherent(dev, 4, &dsi->reg_dma_paddr, GFP_KERNEL); if (!dsi->reg_dma_mem) { @@ -1506,6 +1508,8 @@ static int vc4_dsi_bind(struct device *d return ret; } + /* From here on, any error exits must release the dma channel */ + /* Get the physical address of the device's registers. The * struct resource for the regs gives us the bus address * instead. @@ -1532,7 +1536,7 @@ static int vc4_dsi_bind(struct device *d if (ret) { if (ret != -EPROBE_DEFER) dev_err(dev, "Failed to get interrupt: %d\n", ret); - return ret; + goto rel_dma_exit; } dsi->escape_clock = devm_clk_get(dev, "escape"); @@ -1540,7 +1544,7 @@ static int vc4_dsi_bind(struct device *d ret = PTR_ERR(dsi->escape_clock); if (ret != -EPROBE_DEFER) dev_err(dev, "Failed to get escape clock: %d\n", ret); - return ret; + goto rel_dma_exit; } dsi->pll_phy_clock = devm_clk_get(dev, "phy"); @@ -1548,7 +1552,7 @@ static int vc4_dsi_bind(struct device *d ret = PTR_ERR(dsi->pll_phy_clock); if (ret != -EPROBE_DEFER) dev_err(dev, "Failed to get phy clock: %d\n", ret); - return ret; + goto rel_dma_exit; } dsi->pixel_clock = devm_clk_get(dev, "pixel"); @@ -1556,7 +1560,7 @@ static int vc4_dsi_bind(struct device *d ret = PTR_ERR(dsi->pixel_clock); if (ret != -EPROBE_DEFER) dev_err(dev, "Failed to get pixel clock: %d\n", ret); - return ret; + goto rel_dma_exit; } ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, @@ -1571,26 +1575,28 @@ static int vc4_dsi_bind(struct device *d if (ret == -ENODEV) return 0; - return ret; + goto rel_dma_exit; } if (panel) { dsi->bridge = devm_drm_panel_bridge_add(dev, panel, DRM_MODE_CONNECTOR_DSI); - if (IS_ERR(dsi->bridge)) - return PTR_ERR(dsi->bridge); + if (IS_ERR(dsi->bridge)){ + ret = PTR_ERR(dsi->bridge); + goto rel_dma_exit; + } } /* The esc clock rate is supposed to always be 100Mhz. */ ret = clk_set_rate(dsi->escape_clock, 100 * 1000000); if (ret) { dev_err(dev, "Failed to set esc clock: %d\n", ret); - return ret; + goto rel_dma_exit; } ret = vc4_dsi_init_phy_clocks(dsi); if (ret) - return ret; + goto rel_dma_exit; if (dsi->port == 1) vc4->dsi1 = dsi; @@ -1602,7 +1608,7 @@ static int vc4_dsi_bind(struct device *d ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL); if (ret) { dev_err(dev, "bridge attach failed: %d\n", ret); - return ret; + goto rel_dma_exit; } /* Disable the atomic helper calls into the bridge. We * manually call the bridge pre_enable / enable / etc. calls @@ -1619,6 +1625,11 @@ static int vc4_dsi_bind(struct device *d pm_runtime_enable(dev); return 0; + +rel_dma_exit: + dma_release_channel(dsi->reg_dma_chan); + + return ret; } static void vc4_dsi_unbind(struct device *dev, struct device *master, @@ -1633,6 +1644,8 @@ static void vc4_dsi_unbind(struct device vc4_dsi_encoder_destroy(dsi->encoder); + dma_release_channel(dsi->reg_dma_chan); + if (dsi->port == 1) vc4->dsi1 = NULL; }