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Revision 2b6c53b1504865728a6dfad3e720918a2f89f3a5 authored by Jon Medhurst (Tixy) on 20 August 2014, 12:41:04 UTC, committed by Tomi Valkeinen on 26 August 2014, 09:50:27 UTC 
video: ARM CLCD: Fix calculation of bits-per-pixel
 
If the device-tree specifies a max-memory-bandwidth property then the
CLCD driver uses that to calculate the bits-per-pixel supported,
however, this calculation is faulty for two reasons.

1. It doesn't ensure that the result is a sane value, i.e. a power of 2
   and <= 32 as the rest of the code assumes.

2. It uses the displayed resolution and calculates the average bandwidth
   across the whole frame. It should instead calculate the peak
   bandwidth based on the pixel clock.

This patch fixes both the above.

Signed-off-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
1 parent 754d561
Raw File
decompress.c 
/*
 * decompress.c
 *
 * Detect the decompression method based on magic number
 */

#include <linux/decompress/generic.h>

#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
#include <linux/decompress/unxz.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
#include <linux/decompress/unlz4.h>

#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/printk.h>

#ifndef CONFIG_DECOMPRESS_GZIP
# define gunzip NULL
#endif
#ifndef CONFIG_DECOMPRESS_BZIP2
# define bunzip2 NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZMA
# define unlzma NULL
#endif
#ifndef CONFIG_DECOMPRESS_XZ
# define unxz NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZO
# define unlzo NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZ4
# define unlz4 NULL
#endif

struct compress_format {
	unsigned char magic[2];
	const char *name;
	decompress_fn decompressor;
};

static const struct compress_format compressed_formats[] __initconst = {
	{ {037, 0213}, "gzip", gunzip },
	{ {037, 0236}, "gzip", gunzip },
	{ {0x42, 0x5a}, "bzip2", bunzip2 },
	{ {0x5d, 0x00}, "lzma", unlzma },
	{ {0xfd, 0x37}, "xz", unxz },
	{ {0x89, 0x4c}, "lzo", unlzo },
	{ {0x02, 0x21}, "lz4", unlz4 },
	{ {0, 0}, NULL, NULL }
};

decompress_fn __init decompress_method(const unsigned char *inbuf, long len,
				const char **name)
{
	const struct compress_format *cf;

	if (len < 2)
		return NULL;	/* Need at least this much... */

	pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]);

	for (cf = compressed_formats; cf->name; cf++) {
		if (!memcmp(inbuf, cf->magic, 2))
			break;

	}
	if (name)
		*name = cf->name;
	return cf->decompressor;
}
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