[PATCH 5.19 0409/1157] drm/vc4: dsi: Release workaround buffer and DMA

Greg Kroah-Hartman
2022-08-15T23:45:29Z

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

[ Upstream commit 89c4bbe2a01ea401c2b0fabc104720809084b77f ]

On Pi0-3 the driver allocates a buffer and requests a DMA channel
because the ARM can't write to DSI1's registers directly.

However, we never release that buffer or channel. Let's add a
device-managed action to release each.

Fixes: 4078f5757144 ("drm/vc4: Add DSI driver")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-12-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/vc4/vc4_dsi.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 98308a17e4ed..e82ee94cafc7 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -1487,13 +1487,29 @@ vc4_dsi_init_phy_clocks(struct vc4_dsi *dsi)
dsi->clk_onecell);
}

+static void vc4_dsi_dma_mem_release(void *ptr)
+{
+ struct vc4_dsi *dsi = ptr;
+ struct device *dev = &dsi->pdev->dev;
+
+ dma_free_coherent(dev, 4, dsi->reg_dma_mem, dsi->reg_dma_paddr);
+ dsi->reg_dma_mem = NULL;
+}
+
+static void vc4_dsi_dma_chan_release(void *ptr)
+{
+ struct vc4_dsi *dsi = ptr;
+
+ dma_release_channel(dsi->reg_dma_chan);
+ dsi->reg_dma_chan = NULL;
+}
+
static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
{
struct platform_device *pdev = to_platform_device(dev);
struct drm_device *drm = dev_get_drvdata(master);
struct vc4_dsi *dsi = dev_get_drvdata(dev);
struct vc4_dsi_encoder *vc4_dsi_encoder;
- dma_cap_mask_t dma_mask;
int ret;

dsi->variant = of_device_get_match_data(dev);
@@ -1527,6 +1543,8 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
* so set up a channel for talking to it.
*/
if (dsi->variant->broken_axi_workaround) {
+ dma_cap_mask_t dma_mask;
+
dsi->reg_dma_mem = dma_alloc_coherent(dev, 4,
&dsi->reg_dma_paddr,
GFP_KERNEL);
@@ -1535,8 +1553,13 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
return -ENOMEM;
}

+ ret = devm_add_action_or_reset(dev, vc4_dsi_dma_mem_release, dsi);
+ if (ret)
+ return ret;
+
dma_cap_zero(dma_mask);
dma_cap_set(DMA_MEMCPY, dma_mask);
+
dsi->reg_dma_chan = dma_request_chan_by_mask(&dma_mask);
if (IS_ERR(dsi->reg_dma_chan)) {
ret = PTR_ERR(dsi->reg_dma_chan);
@@ -1546,6 +1569,10 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
return ret;
}

+ ret = devm_add_action_or_reset(dev, vc4_dsi_dma_chan_release, dsi);
+ if (ret)
+ return ret;
+
/* Get the physical address of the device's registers. The
* struct resource for the regs gives us the bus address
* instead.
--
2.35.1