Re: [PATCH] ide-cd: fix endianity for the error message in cdrom_read_capacity

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Wednesday 30 July 2008, Boris Petkov wrote:
> On Wed, Jul 30, 2008 at 10:18 AM, Andrew Morton
> <akpm@linux-foundation.org> wrote:
> > On Wed, 30 Jul 2008 10:10:06 +0200 Petr Tesarik <ptesarik@suse.cz> wrote:
> >
> >> Resent because of a typo in the LKML address. :(
> >
> > Thanks.
> >
> >>
> >> Aesthetic regards aside, commit e8e7b9eb11c34ee18bde8b7011af41938d1ad667
> >> still leaves a bug in the error message, because it uses the unconverted
> >> big-endian value for printk.

speaking of aesthetics: __u32 -> u32 ;-)

> >> Fix this by using a local variable in machine byte order. The result is
> >> correct, more readable, and also produces slightly shorter code on i386.
> >>
> >> Cc: Jens Axboe <jens.axboe@oracle.com>
> >> Cc: Jan Kara <jack@suse.cz>
> >> Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
> 
> I definitely like this one better, thanks.
> 
> Acked-by: Borislav Petkov <petkovbb@gmail.com>

applied

> > Bart owns this patch now.  It got lost for a month and it has already
> > been fixed twice and it is also on the route to 2.6.25.x and 2.6.26.x,
> > so it'll get complicated.  Not a happy little patch.
> 
> Greg, can you please apply this one on top of -stable.

The usual policy is to not apply to -stable patches which are not in
Linus' tree so please notify stable@kernelorg team after patch hits
mainline.

> >
> >>
> >>  ide-cd.c |   18 ++++++++++--------
> >>  1 file changed, 10 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
> >> --- a/drivers/ide/ide-cd.c
> >> +++ b/drivers/ide/ide-cd.c
> >> @@ -1305,6 +1305,7 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
> >>       int stat;
> >>       unsigned char cmd[BLK_MAX_CDB];
> >>       unsigned len = sizeof(capbuf);
> >> +     __u32 blocklen;
> >>
> >>       memset(cmd, 0, BLK_MAX_CDB);
> >>       cmd[0] = GPCMD_READ_CDVD_CAPACITY;
> >> @@ -1317,23 +1318,24 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
> >>       /*
> >>        * Sanity check the given block size
> >>        */
> >> -     switch (capbuf.blocklen) {
> >> -     case __constant_cpu_to_be32(512):
> >> -     case __constant_cpu_to_be32(1024):
> >> -     case __constant_cpu_to_be32(2048):
> >> -     case __constant_cpu_to_be32(4096):
> >> +     blocklen = be32_to_cpu(capbuf.blocklen);
> >> +     switch (blocklen) {
> >> +     case 512:
> >> +     case 1024:
> >> +     case 2048:
> >> +     case 4096:
> >>               break;
> >>       default:
> >>               printk(KERN_ERR "%s: weird block size %u\n",
> >> -                     drive->name, capbuf.blocklen);
> >> +                     drive->name, blocklen);
> >>               printk(KERN_ERR "%s: default to 2kb block size\n",
> >>                       drive->name);
> >> -             capbuf.blocklen = __constant_cpu_to_be32(2048);
> >> +             blocklen = 2048;
> >>               break;
> >>       }
> >>
> >>       *capacity = 1 + be32_to_cpu(capbuf.lba);
> >> -     *sectors_per_frame = be32_to_cpu(capbuf.blocklen) >> SECTOR_BITS;
> >> +     *sectors_per_frame = blocklen >> SECTOR_BITS;
> >>       return 0;
> >>  }