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Commit 031e9127 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Sascha Hauer
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ARM: mx3/mx31moboard: properly allocate memory for mx3-camera 



It's not allowed to create an alias of system RAM for DMA.  So the memory
used must not be allocated using dma_alloc_coherent but has to be reserved
before using memblock routines.

There is no need to memzero the buffer because dma_alloc_coherent zeros
the memory for us.

LAKML-Reference: 1299271882-2130-4-git-send-email-u.kleine-koenig@pengutronix.de
Tested-by: default avatarPhilippe Retornaz <philippe.retornaz@epfl.ch>
Acked-by: default avatarPhilippe Retornaz <philippe.retornaz@epfl.ch>
Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
parent dca7c0b4

arch/arm/mach-mx3/mach-mx31moboard.c

+17 −16
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/mfd/mc13783.h>

#include <linux/spi/spi.h>

#include <linux/types.h>

#include <linux/memblock.h>



#include <linux/usb/otg.h>

#include <linux/usb/ulpi.h>
@@ -472,27 +473,17 @@ static struct mx3_camera_pdata camera_pdata = { 
	.mclk_10khz	= 4800,

};



#define CAMERA_BUF_SIZE	(4*1024*1024)

static phys_addr_t mx3_camera_base __initdata;

#define MX3_CAMERA_BUF_SIZE SZ_4M



static int __init mx31moboard_cam_alloc_dma(const size_t buf_size)

static int __init mx31moboard_cam_alloc_dma(void)

{

	dma_addr_t dma_handle;

	void *buf;

	int dma;



	if (buf_size < 2 * 1024 * 1024)

		return -EINVAL;



	buf = dma_alloc_coherent(NULL, buf_size, &dma_handle, GFP_KERNEL);

	if (!buf) {

		pr_err("%s: cannot allocate camera buffer-memory\n", __func__);

		return -ENOMEM;

	}



	memset(buf, 0, buf_size);



	dma = dma_declare_coherent_memory(&mx3_camera.dev,

					dma_handle, dma_handle, buf_size,

					mx3_camera_base, mx3_camera_base,

					MX3_CAMERA_BUF_SIZE,

					DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);



	/* The way we call dma_declare_coherent_memory only a malloc can fail */
@@ -529,7 +520,7 @@ static void __init mx31moboard_init(void) 
	imx31_add_mxc_mmc(0, &sdhc1_pdata);



	mxc_register_device(&mx3_ipu, &mx3_ipu_data);

	if (!mx31moboard_cam_alloc_dma(CAMERA_BUF_SIZE))

	if (!mx31moboard_cam_alloc_dma())

		mxc_register_device(&mx3_camera, &camera_pdata);



	usb_xcvr_reset();
@@ -564,9 +555,19 @@ struct sys_timer mx31moboard_timer = { 
	.init	= mx31moboard_timer_init,

};



static void __init mx31moboard_reserve(void)

{

	/* reserve 4 MiB for mx3-camera */

	mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,

			MX3_CAMERA_BUF_SIZE);

	memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);

	memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);

}



MACHINE_START(MX31MOBOARD, "EPFL Mobots mx31moboard")

	/* Maintainer: Valentin Longchamp, EPFL Mobots group */

	.boot_params = MX3x_PHYS_OFFSET + 0x100,

	.reserve = mx31moboard_reserve,

	.map_io = mx31_map_io,

	.init_early = imx31_init_early,

	.init_irq = mx31_init_irq,