Skip to main content

Browse the archive

Revision 72741084d903e65e121c27bd29494d941729d4a1 authored by Ulf Hansson on 27 August 2019, 08:10:43 UTC, committed by Ulf Hansson on 30 August 2019, 07:17:53 UTC 
mmc: core: Fix init of SD cards reporting an invalid VDD range
 
The OCR register defines the supported range of VDD voltages for SD cards.
However, it has turned out that some SD cards reports an invalid voltage
range, for example having bit7 set.

When a host supports MMC_CAP2_FULL_PWR_CYCLE and some of the voltages from
the invalid VDD range, this triggers the core to run a power cycle of the
card to try to initialize it at the lowest common supported voltage.
Obviously this fails, since the card can't support it.

Let's fix this problem, by clearing invalid bits from the read OCR register
for SD cards, before proceeding with the VDD voltage negotiation.

Cc: stable@vger.kernel.org
Reported-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Philip Langdale <philipl@overt.org>
Tested-by: Philip Langdale <philipl@overt.org>
Tested-by: Manuel Presnitz <mail@mpy.de>
1 parent 7871aa6
Raw File
mmap-nommu.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/* NOMMU mmap support for RomFS on MTD devices
 *
 * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/mm.h>
#include <linux/mtd/super.h>
#include "internal.h"

/*
 * try to determine where a shared mapping can be made
 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 *   mappings)
 * - attempts to map through to the underlying MTD device
 */
static unsigned long romfs_get_unmapped_area(struct file *file,
					     unsigned long addr,
					     unsigned long len,
					     unsigned long pgoff,
					     unsigned long flags)
{
	struct inode *inode = file->f_mapping->host;
	struct mtd_info *mtd = inode->i_sb->s_mtd;
	unsigned long isize, offset, maxpages, lpages;
	int ret;

	if (!mtd)
		return (unsigned long) -ENOSYS;

	/* the mapping mustn't extend beyond the EOF */
	lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
	isize = i_size_read(inode);
	offset = pgoff << PAGE_SHIFT;

	maxpages = (isize + PAGE_SIZE - 1) >> PAGE_SHIFT;
	if ((pgoff >= maxpages) || (maxpages - pgoff < lpages))
		return (unsigned long) -EINVAL;

	if (addr != 0)
		return (unsigned long) -EINVAL;

	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
		return (unsigned long) -EINVAL;

	offset += ROMFS_I(inode)->i_dataoffset;
	if (offset >= mtd->size)
		return (unsigned long) -EINVAL;
	/* the mapping mustn't extend beyond the EOF */
	if ((offset + len) > mtd->size)
		len = mtd->size - offset;

	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
	if (ret == -EOPNOTSUPP)
		ret = -ENOSYS;
	return (unsigned long) ret;
}

/*
 * permit a R/O mapping to be made directly through onto an MTD device if
 * possible
 */
static int romfs_mmap(struct file *file, struct vm_area_struct *vma)
{
	return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS;
}

static unsigned romfs_mmap_capabilities(struct file *file)
{
	struct mtd_info *mtd = file_inode(file)->i_sb->s_mtd;

	if (!mtd)
		return NOMMU_MAP_COPY;
	return mtd_mmap_capabilities(mtd);
}

const struct file_operations romfs_ro_fops = {
	.llseek			= generic_file_llseek,
	.read_iter		= generic_file_read_iter,
	.splice_read		= generic_file_splice_read,
	.mmap			= romfs_mmap,
	.get_unmapped_area	= romfs_get_unmapped_area,
	.mmap_capabilities	= romfs_mmap_capabilities,
};
back to top