libata-sff: fix 32-bit PIO ATAPI regression
Commit 871af1210f
(libata: Add 32bit
PIO support) has caused all kinds of errors on the ATAPI devices, so
it has been empirically proven that one shouldn't try to read/write
an extra data word when a device is not expecting it already. "Don't
do it then"; however, still use a chance to do 32-bit read/write one
last time when there are exactly 3 trailing bytes.
Oh, and stop pointlessly swapping the bytes to and fro on big-endian
machines by using io*_rep() accessors which shouldn't byte-swap.
This patch should fix the kernel.org bug #12609.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
parent
d2f8d7ee1a
commit
d1b3525b41
|
@ -773,18 +773,32 @@ unsigned int ata_sff_data_xfer32(struct ata_device *dev, unsigned char *buf,
|
|||
else
|
||||
iowrite32_rep(data_addr, buf, words);
|
||||
|
||||
/* Transfer trailing bytes, if any */
|
||||
if (unlikely(slop)) {
|
||||
__le32 pad;
|
||||
unsigned char pad[4];
|
||||
|
||||
/* Point buf to the tail of buffer */
|
||||
buf += buflen - slop;
|
||||
|
||||
/*
|
||||
* Use io*_rep() accessors here as well to avoid pointlessly
|
||||
* swapping bytes to and fro on the big endian machines...
|
||||
*/
|
||||
if (rw == READ) {
|
||||
pad = cpu_to_le32(ioread32(ap->ioaddr.data_addr));
|
||||
memcpy(buf + buflen - slop, &pad, slop);
|
||||
if (slop < 3)
|
||||
ioread16_rep(data_addr, pad, 1);
|
||||
else
|
||||
ioread32_rep(data_addr, pad, 1);
|
||||
memcpy(buf, pad, slop);
|
||||
} else {
|
||||
memcpy(&pad, buf + buflen - slop, slop);
|
||||
iowrite32(le32_to_cpu(pad), ap->ioaddr.data_addr);
|
||||
memcpy(pad, buf, slop);
|
||||
if (slop < 3)
|
||||
iowrite16_rep(data_addr, pad, 1);
|
||||
else
|
||||
iowrite32_rep(data_addr, pad, 1);
|
||||
}
|
||||
words++;
|
||||
}
|
||||
return words << 2;
|
||||
return (buflen + 1) & ~1;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(ata_sff_data_xfer32);
|
||||
|
||||
|
|
Loading…
Reference in New Issue