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SubjectRe: 2.1.10 FYI

On Fri, 15 Nov 1996, Erik B. Andersen wrote:

> >From the latest version of Documentation/cdrom/cdrom-standard.tex:
>
> ... These parameters are declared $const$ because they describe properties
> of the drive, which don't change after registration. ... The
> capability flag is declared $const$, to prevent drivers from
> accidentally tampering with the contents.
>
> The patch you submitted for ucdrom.h is the WrongThing(tm). These values
> must be set during drive registration, but they should be declared const so
> that nothing can change them subsequently (thereby screwing up the kernel).
> [ ... ]
> The ide-cd driver simply adds a cast to suppress the compiler warning.
> This allows you to set the const values on drive initialization without
> warnings. Just don't do this somewhere else in your code... This is the
> RightThing(tm) to do, IMHO. Do something like this to sr.c:
>
> ---> *(int *)&devinfo->speed = 0;
> ---> *(int *)&devinfo->capacity = nslots;

Hmm, does'nt sound perfect either. But maybe the best way we have to
handle these "write-once" variables. Here comes the patch for sr.c.

Gerd

---------------------------------------------------------------------
--- linux/drivers/scsi/sr.c-2.1.10 Sat Nov 16 09:17:18 1996
+++ linux/drivers/scsi/sr.c Sat Nov 16 09:22:38 1996
@@ -793,8 +793,8 @@
scsi_CDs[i].cdi.handle = &scsi_CDs[i];
scsi_CDs[i].cdi.dev = MKDEV(MAJOR_NR,i);
scsi_CDs[i].cdi.mask = 0;
- scsi_CDs[i].cdi.speed = 1;
- scsi_CDs[i].cdi.capacity = 1;
+ (int)scsi_CDs[i].cdi.speed = 1;
+ (int)scsi_CDs[i].cdi.capacity = 1;
register_cdrom(&scsi_CDs[i].cdi, "sr");

#ifdef CONFIG_BLK_DEV_SR_VENDOR

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