1 --- a/drivers/mtd/mtdpart.c
2 +++ b/drivers/mtd/mtdpart.c
5 #include "mtdsplit/mtdsplit.h"
7 +#define MTD_ERASE_PARTIAL 0x8000 /* partition only covers parts of an erase block */
9 /* Our partition linked list */
10 static LIST_HEAD(mtd_partitions);
11 static DEFINE_MUTEX(mtd_partitions_mutex);
12 @@ -236,13 +238,61 @@ static int part_erase(struct mtd_info *m
13 struct mtd_part *part = PART(mtd);
17 + instr->partial_start = false;
18 + if (mtd->flags & MTD_ERASE_PARTIAL) {
22 + instr->erase_buf = kmalloc(part->master->erasesize, GFP_ATOMIC);
23 + if (!instr->erase_buf)
26 + mtd_ofs = part->offset + instr->addr;
27 + instr->erase_buf_ofs = do_div(mtd_ofs, part->master->erasesize);
29 + if (instr->erase_buf_ofs > 0) {
30 + instr->addr -= instr->erase_buf_ofs;
31 + ret = mtd_read(part->master,
32 + instr->addr + part->offset,
33 + part->master->erasesize,
34 + &readlen, instr->erase_buf);
36 + instr->len += instr->erase_buf_ofs;
37 + instr->partial_start = true;
39 + mtd_ofs = part->offset + part->mtd.size;
40 + instr->erase_buf_ofs = part->master->erasesize -
41 + do_div(mtd_ofs, part->master->erasesize);
43 + if (instr->erase_buf_ofs > 0) {
44 + instr->len += instr->erase_buf_ofs;
45 + ret = mtd_read(part->master,
46 + part->offset + instr->addr +
47 + instr->len - part->master->erasesize,
48 + part->master->erasesize, &readlen,
55 + kfree(instr->erase_buf);
61 instr->addr += part->offset;
62 ret = part->master->_erase(part->master, instr);
64 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
65 instr->fail_addr -= part->offset;
66 instr->addr -= part->offset;
67 + if (mtd->flags & MTD_ERASE_PARTIAL)
68 + kfree(instr->erase_buf);
74 @@ -250,7 +300,25 @@ void mtd_erase_callback(struct erase_inf
76 if (instr->mtd->_erase == part_erase) {
77 struct mtd_part *part = PART(instr->mtd);
80 + if (instr->mtd->flags & MTD_ERASE_PARTIAL) {
81 + if (instr->partial_start) {
82 + part->master->_write(part->master,
83 + instr->addr, instr->erase_buf_ofs,
84 + &wrlen, instr->erase_buf);
85 + instr->addr += instr->erase_buf_ofs;
87 + instr->len -= instr->erase_buf_ofs;
88 + part->master->_write(part->master,
89 + instr->addr + instr->len,
90 + instr->erase_buf_ofs, &wrlen,
92 + part->master->erasesize -
93 + instr->erase_buf_ofs);
95 + kfree(instr->erase_buf);
97 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
98 instr->fail_addr -= part->offset;
99 instr->addr -= part->offset;
100 @@ -523,17 +591,20 @@ static struct mtd_part *allocate_partiti
101 if ((slave->mtd.flags & MTD_WRITEABLE) &&
102 mtd_mod_by_eb(slave->offset, &slave->mtd)) {
103 /* Doesn't start on a boundary of major erase size */
104 - /* FIXME: Let it be writable if it is on a boundary of
105 - * _minor_ erase size though */
106 - slave->mtd.flags &= ~MTD_WRITEABLE;
107 - printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
109 + slave->mtd.flags |= MTD_ERASE_PARTIAL;
110 + if (((u32) slave->mtd.size) > master->erasesize)
111 + slave->mtd.flags &= ~MTD_WRITEABLE;
113 + slave->mtd.erasesize = slave->mtd.size;
115 if ((slave->mtd.flags & MTD_WRITEABLE) &&
116 - mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
117 - slave->mtd.flags &= ~MTD_WRITEABLE;
118 - printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
120 + mtd_mod_by_eb(slave->offset + slave->mtd.size, &slave->mtd)) {
121 + slave->mtd.flags |= MTD_ERASE_PARTIAL;
123 + if ((u32) slave->mtd.size > master->erasesize)
124 + slave->mtd.flags &= ~MTD_WRITEABLE;
126 + slave->mtd.erasesize = slave->mtd.size;
129 slave->mtd.ecclayout = master->ecclayout;
130 --- a/include/linux/mtd/mtd.h
131 +++ b/include/linux/mtd/mtd.h
132 @@ -55,6 +55,10 @@ struct erase_info {
135 struct erase_info *next;
139 + bool partial_start;
142 struct mtd_erase_region_info {