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From 496b26b154da9a962a5310641d8f4b73200fe590 Mon Sep 17 00:00:00 2001
From: Chris Miller <chris@mesl2.co.uk>
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 <chris@creative-electronics.net>
---
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
@@ -1536,9 +1536,11 @@ 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) {
@@ -1557,6 +1559,8 @@ 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.
@@ -1583,7 +1587,7 @@ 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");
@@ -1591,7 +1595,7 @@ 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");
@@ -1599,7 +1603,7 @@ 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");
@@ -1607,7 +1611,7 @@ 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,
@@ -1622,26 +1626,28 @@ 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;
@@ -1653,7 +1659,7 @@ 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
@@ -1665,6 +1671,11 @@ 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,
@@ -1679,6 +1690,8 @@ 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;
}
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