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SubjectRe: recent IDE regression


On Fri, 25 Jul 2008, Ben Dooks wrote:
>
> personally, i would much prefer to see the loop being less evil
> like:
>
> for (p = s; p < end; p += 2)
> be16_to_cpus((u16 *)p);

Well, in this case, the code actually depends on 'p' being back at the
start of the buffer by the end of it all, so it would need some more
changes than that.

But yes, I applied David's patch, but I _also_ suspect that we would be
better off without code that does horrid things like casts and assignments
inside the function arguments.

So it would be nice to re-code that loop to be more readable. But due to
the reliance of 'p' being 's' after the loop, the minimal patch would be
something like the appended.

Bartlomiej - take this or not, I'm not going to commit it - I haven't
tested it, nor do I even have any machines that would trigger it. So this
is more a "maybe something like this" than anything else.

Linus

---
drivers/ide/ide-iops.c | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 8aae917..ae03151 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -506,14 +506,16 @@ void ide_fix_driveid (struct hd_driveid *id)

void ide_fixstring (u8 *s, const int bytecount, const int byteswap)
{
- u8 *p = s, *end = &s[bytecount & ~1]; /* bytecount must be even */
+ u8 *p, *end = &s[bytecount & ~1]; /* bytecount must be even */

if (byteswap) {
/* convert from big-endian to host byte order */
- for (p = end ; p != s;)
- be16_to_cpus((u16 *)(p -= 2));
+ for (p = s ; p != end ; p += 2)
+ be16_to_cpus((u16 *) p);
}
+
/* strip leading blanks */
+ p = s;
while (s != end && *s == ' ')
++s;
/* compress internal blanks and strip trailing blanks */

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