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

   1 From 51f5523151d8de2b1476482e575bb5989e55ba16 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Tue, 6 Jul 2021 18:53:28 +0100
   4 Subject: [PATCH] drm/vc4: Release workaround buffer and DMA in error
   5  paths and unbind
   6
   7 On Pi0-3 the driver allocates a buffer and requests a DMA channel
   8 because the ARM can't write to DSI1's registers directly.
   9 However unbind and the error paths in bind don't release the buffer or
  10 the DMA channel.
  11
  12 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  13 ---
  14  drivers/gpu/drm/vc4/vc4_dsi.c | 51 ++++++++++++++++++++++++++---------
  15  1 file changed, 39 insertions(+), 12 deletions(-)
  16
  17 --- a/drivers/gpu/drm/vc4/vc4_dsi.c
  18 +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
  19 @@ -1612,7 +1612,7 @@ static int vc4_dsi_bind(struct device *d
  20                         if (ret != -EPROBE_DEFER)
  21                                 DRM_ERROR("Failed to get DMA channel: %d\n",
  22                                           ret);
  23 -                       return ret;
  24 +                       goto err_free_dma_mem;
  25                 }
  26
  27                 /* Get the physical address of the device's registers.  The
  28 @@ -1641,7 +1641,7 @@ static int vc4_dsi_bind(struct device *d
  29         if (ret) {
  30                 if (ret != -EPROBE_DEFER)
  31                         dev_err(dev, "Failed to get interrupt: %d\n", ret);
  32 -               return ret;
  33 +               goto err_free_dma;
  34         }
  35
  36         dsi->escape_clock = devm_clk_get(dev, "escape");
  37 @@ -1649,7 +1649,7 @@ static int vc4_dsi_bind(struct device *d
  38                 ret = PTR_ERR(dsi->escape_clock);
  39                 if (ret != -EPROBE_DEFER)
  40                         dev_err(dev, "Failed to get escape clock: %d\n", ret);
  41 -               return ret;
  42 +               goto err_free_dma;
  43         }
  44
  45         dsi->pll_phy_clock = devm_clk_get(dev, "phy");
  46 @@ -1657,7 +1657,7 @@ static int vc4_dsi_bind(struct device *d
  47                 ret = PTR_ERR(dsi->pll_phy_clock);
  48                 if (ret != -EPROBE_DEFER)
  49                         dev_err(dev, "Failed to get phy clock: %d\n", ret);
  50 -               return ret;
  51 +               goto err_free_dma;
  52         }
  53
  54         dsi->pixel_clock = devm_clk_get(dev, "pixel");
  55 @@ -1665,7 +1665,7 @@ static int vc4_dsi_bind(struct device *d
  56                 ret = PTR_ERR(dsi->pixel_clock);
  57                 if (ret != -EPROBE_DEFER)
  58                         dev_err(dev, "Failed to get pixel clock: %d\n", ret);
  59 -               return ret;
  60 +               goto err_free_dma;
  61         }
  62
  63         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
  64 @@ -1680,33 +1680,37 @@ static int vc4_dsi_bind(struct device *d
  65                 if (ret == -ENODEV)
  66                         return 0;
  67
  68 -               return ret;
  69 +               goto err_free_dma;
  70         }
  71
  72         if (panel) {
  73                 dsi->bridge = devm_drm_panel_bridge_add_typed(dev, panel,
  74                                                               DRM_MODE_CONNECTOR_DSI);
  75 -               if (IS_ERR(dsi->bridge))
  76 -                       return PTR_ERR(dsi->bridge);
  77 +               if (IS_ERR(dsi->bridge)) {
  78 +                       ret = PTR_ERR(dsi->bridge);
  79 +                       goto err_free_dma;
  80 +               }
  81         }
  82
  83         /* The esc clock rate is supposed to always be 100Mhz. */
  84         ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
  85         if (ret) {
  86                 dev_err(dev, "Failed to set esc clock: %d\n", ret);
  87 -               return ret;
  88 +               goto err_free_dma;
  89         }
  90
  91         ret = vc4_dsi_init_phy_clocks(dsi);
  92         if (ret)
  93 -               return ret;
  94 +               goto err_free_dma;
  95
  96         drm_simple_encoder_init(drm, dsi->encoder, DRM_MODE_ENCODER_DSI);
  97         drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);
  98
  99         ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL, 0);
 100 -       if (ret)
 101 -               return ret;
 102 +       if (ret) {
 103 +               dev_err(dev, "bridge attach failed: %d\n", ret);
 104 +               goto err_free_dma;
 105 +       }
 106         /* Disable the atomic helper calls into the bridge.  We
 107          * manually call the bridge pre_enable / enable / etc. calls
 108          * from our driver, since we need to sequence them within the
 109 @@ -1719,6 +1723,19 @@ static int vc4_dsi_bind(struct device *d
 110         pm_runtime_enable(dev);
 111
 112         return 0;
 113 +
 114 +err_free_dma:
 115 +       if (dsi->reg_dma_chan) {
 116 +               dma_release_channel(dsi->reg_dma_chan);
 117 +               dsi->reg_dma_chan = NULL;
 118 +       }
 119 +err_free_dma_mem:
 120 +       if (dsi->reg_dma_mem) {
 121 +               dma_free_coherent(dev, 4, dsi->reg_dma_mem, dsi->reg_dma_paddr);
 122 +               dsi->reg_dma_mem = NULL;
 123 +       }
 124 +
 125 +       return ret;
 126  }
 127
 128  static void vc4_dsi_unbind(struct device *dev, struct device *master,
 129 @@ -1735,6 +1752,16 @@ static void vc4_dsi_unbind(struct device
 130          */
 131         list_splice_init(&dsi->bridge_chain, &dsi->encoder->bridge_chain);
 132         drm_encoder_cleanup(dsi->encoder);
 133 +
 134 +       if (dsi->reg_dma_chan) {
 135 +               dma_release_channel(dsi->reg_dma_chan);
 136 +               dsi->reg_dma_chan = NULL;
 137 +       }
 138 +
 139 +       if (dsi->reg_dma_mem) {
 140 +               dma_free_coherent(dev, 4, dsi->reg_dma_mem, dsi->reg_dma_paddr);
 141 +               dsi->reg_dma_mem = NULL;
 142 +       }
 143  }
 144
 145  static const struct component_ops vc4_dsi_ops = {