OMAP1 camera driver, when starting up in its videobuf_contig mode, may have
problems with allocating dma coherent memory after system memory gets
fragmented if there is no dedicated memory declared as a dma coherent memory
block associated with the device. To solve this issue, allow for removing a
block of memory from system memory early on boot, then, if reserved this way,
declare it as the device dedicated dma coherent memory.
An example use case on Amstrad Delta will be provided with patch 2/2.
Created and tested against linux-2.6.37-rc4.
Signed-off-by: Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx>
---
arch/arm/mach-omap1/devices.c | 36 ++++++++++++++++++++++++++++++
arch/arm/mach-omap1/include/mach/camera.h | 1
2 files changed, 37 insertions(+)
--- linux-2.6.37-rc4/arch/arm/mach-omap1/devices.c.orig 2010-12-04 18:00:39.000000000 +0100
+++ linux-2.6.37-rc4/arch/arm/mach-omap1/devices.c 2010-12-04 22:22:13.000000000 +0100
@@ -16,6 +16,7 @@
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/spi/spi.h>
+#include <linux/memblock.h>
#include <mach/hardware.h>
#include <asm/mach/map.h>
@@ -222,13 +223,48 @@ static struct platform_device omap1_came
.resource = omap1_camera_resources,
};
+static phys_addr_t omap1_camera_phys_mempool_base;
+static phys_addr_t omap1_camera_phys_mempool_size;
+
+void __init omap1_camera_reserve(phys_addr_t size)
+{
+ phys_addr_t paddr;
+
+ if (!size)
+ return;
+
+ paddr = memblock_alloc(size, SZ_1M);
+
+ if (!paddr) {
+ pr_err("%s: failed to reserve %x bytes\n", __func__, size);
+ return;
+ }
+ memblock_free(paddr, size);
+ memblock_remove(paddr, size);
+
+ omap1_camera_phys_mempool_base = paddr;
+ omap1_camera_phys_mempool_size = size;
+}
+
void __init omap1_camera_init(void *info)
{
struct platform_device *dev = &omap1_camera_device;
+ dma_addr_t paddr = omap1_camera_phys_mempool_base;
+ dma_addr_t size = omap1_camera_phys_mempool_size;
int ret;
dev->dev.platform_data = info;
+ if (paddr) {
+ if (dma_declare_coherent_memory(&dev->dev, paddr, paddr, size,
+ DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE))
+ pr_info("%s: reserved %d bytes camera buffer memory\n",
+ __func__, size);
+ else
+ pr_warn("%s: cannot reserve camera buffer memory\n",
+ __func__);
+ }
+
ret = platform_device_register(dev);
if (ret)
dev_err(&dev->dev, "unable to register device: %d\n", ret);
--- linux-2.6.37-rc4/arch/arm/mach-omap1/include/mach/camera.h.orig 2010-12-04 18:00:39.000000000 +0100
+++ linux-2.6.37-rc4/arch/arm/mach-omap1/include/mach/camera.h 2010-12-04 22:26:23.000000000 +0100
@@ -3,6 +3,7 @@
#include <media/omap1_camera.h>
+void omap1_camera_reserve(phys_addr_t);
void omap1_camera_init(void *);
static inline void omap1_set_camera_info(struct omap1_cam_platform_data *info)
--
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