git.openwrt.org Git - openwrt/staging/981213.git/blob

   1 From cbda8e6de54f8a0f194e990f53e1cfad642af1be Mon Sep 17 00:00:00 2001
   2 From: Chris Miller <chris@mesl2.co.uk>
   3 Date: Wed, 26 Jun 2019 10:40:30 +0100
   4 Subject: [PATCH] drm: vc4_dsi: Fix DMA channel and memory leak in vc4
   5  (#3012)
   6
   7 Signed-off-by: Chris G Miller <chris@creative-electronics.net>
   8 ---
   9  drivers/gpu/drm/vc4/vc4_dsi.c | 35 ++++++++++++++++++++++++-----------
  10  1 file changed, 24 insertions(+), 11 deletions(-)
  11
  12 --- a/drivers/gpu/drm/vc4/vc4_dsi.c
  13 +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
  14 @@ -1485,9 +1485,11 @@ static int vc4_dsi_bind(struct device *d
  15         /* DSI1 has a broken AXI slave that doesn't respond to writes
  16          * from the ARM.  It does handle writes from the DMA engine,
  17          * so set up a channel for talking to it.
  18 +        * Where possible managed resource providers are used, but the DMA channel
  19 +        * must - if acquired - be explicitly released prior to taking an error exit path.
  20          */
  21         if (dsi->port == 1) {
  22 -               dsi->reg_dma_mem = dma_alloc_coherent(dev, 4,
  23 +               dsi->reg_dma_mem = dmam_alloc_coherent(dev, 4,
  24                                                       &dsi->reg_dma_paddr,
  25                                                       GFP_KERNEL);
  26                 if (!dsi->reg_dma_mem) {
  27 @@ -1506,6 +1508,8 @@ static int vc4_dsi_bind(struct device *d
  28                         return ret;
  29                 }
  30
  31 +               /* From here on, any error exits must release the dma channel */
  32 +
  33                 /* Get the physical address of the device's registers.  The
  34                  * struct resource for the regs gives us the bus address
  35                  * instead.
  36 @@ -1532,7 +1536,7 @@ static int vc4_dsi_bind(struct device *d
  37         if (ret) {
  38                 if (ret != -EPROBE_DEFER)
  39                         dev_err(dev, "Failed to get interrupt: %d\n", ret);
  40 -               return ret;
  41 +               goto rel_dma_exit;
  42         }
  43
  44         dsi->escape_clock = devm_clk_get(dev, "escape");
  45 @@ -1540,7 +1544,7 @@ static int vc4_dsi_bind(struct device *d
  46                 ret = PTR_ERR(dsi->escape_clock);
  47                 if (ret != -EPROBE_DEFER)
  48                         dev_err(dev, "Failed to get escape clock: %d\n", ret);
  49 -               return ret;
  50 +               goto rel_dma_exit;
  51         }
  52
  53         dsi->pll_phy_clock = devm_clk_get(dev, "phy");
  54 @@ -1548,7 +1552,7 @@ static int vc4_dsi_bind(struct device *d
  55                 ret = PTR_ERR(dsi->pll_phy_clock);
  56                 if (ret != -EPROBE_DEFER)
  57                         dev_err(dev, "Failed to get phy clock: %d\n", ret);
  58 -               return ret;
  59 +               goto rel_dma_exit;
  60         }
  61
  62         dsi->pixel_clock = devm_clk_get(dev, "pixel");
  63 @@ -1556,7 +1560,7 @@ static int vc4_dsi_bind(struct device *d
  64                 ret = PTR_ERR(dsi->pixel_clock);
  65                 if (ret != -EPROBE_DEFER)
  66                         dev_err(dev, "Failed to get pixel clock: %d\n", ret);
  67 -               return ret;
  68 +               goto rel_dma_exit;
  69         }
  70
  71         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
  72 @@ -1571,26 +1575,28 @@ static int vc4_dsi_bind(struct device *d
  73                 if (ret == -ENODEV)
  74                         return 0;
  75
  76 -               return ret;
  77 +               goto rel_dma_exit;
  78         }
  79
  80         if (panel) {
  81                 dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
  82                                                         DRM_MODE_CONNECTOR_DSI);
  83 -               if (IS_ERR(dsi->bridge))
  84 -                       return PTR_ERR(dsi->bridge);
  85 +               if (IS_ERR(dsi->bridge)){
  86 +                       ret = PTR_ERR(dsi->bridge);
  87 +                       goto rel_dma_exit;
  88 +               }
  89         }
  90
  91         /* The esc clock rate is supposed to always be 100Mhz. */
  92         ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
  93         if (ret) {
  94                 dev_err(dev, "Failed to set esc clock: %d\n", ret);
  95 -               return ret;
  96 +               goto rel_dma_exit;
  97         }
  98
  99         ret = vc4_dsi_init_phy_clocks(dsi);
 100         if (ret)
 101 -               return ret;
 102 +               goto rel_dma_exit;
 103
 104         if (dsi->port == 1)
 105                 vc4->dsi1 = dsi;
 106 @@ -1602,7 +1608,7 @@ static int vc4_dsi_bind(struct device *d
 107         ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
 108         if (ret) {
 109                 dev_err(dev, "bridge attach failed: %d\n", ret);
 110 -               return ret;
 111 +               goto rel_dma_exit;
 112         }
 113         /* Disable the atomic helper calls into the bridge.  We
 114          * manually call the bridge pre_enable / enable / etc. calls
 115 @@ -1619,6 +1625,11 @@ static int vc4_dsi_bind(struct device *d
 116         pm_runtime_enable(dev);
 117
 118         return 0;
 119 +
 120 +rel_dma_exit:
 121 +       dma_release_channel(dsi->reg_dma_chan);
 122 +
 123 +       return ret;
 124  }
 125
 126  static void vc4_dsi_unbind(struct device *dev, struct device *master,
 127 @@ -1633,6 +1644,8 @@ static void vc4_dsi_unbind(struct device
 128
 129         vc4_dsi_encoder_destroy(dsi->encoder);
 130
 131 +       dma_release_channel(dsi->reg_dma_chan);
 132 +
 133         if (dsi->port == 1)
 134                 vc4->dsi1 = NULL;
 135  }