Re: [PATCH] CDC_MMC_WR

[Pat LaVarre <p.lavarre@ieee.org>]

> Does the ->writeable bit exist for ide-cd devices, or only for sr
> devices?

I'm guessing only sr devices, since grep writeable fails in drivers/ide/
and in drivers/cdrom/.

> When cdrom.ko decides a device is not writable, how does cdrom.ko name
> that bit, else how does cdrom.ko call into ide-cd/sr to clear that bit?

Call back into sr from cdrom may occur via the cdrom_device_ops.

We define cdrom_ioctl CDROM_GET_CAPABILITY but no SET of capability,
though we do define CDROM_SET_OPTIONS.

Maybe we're telling me to add a call back to the cdrom_device_ops for
cdrom to notify ide-cd/sr that the capabilities have changed.  ide-cd
could ignore that notification, sr could set
scsi_cd->scsi_device->writeable accordingly.

> Have "the ->writeable bit actually be set if the device is writeable".

grep is failing to find code for me that fetches this bit.

Is this bit ever fetched?

http://lxr.linux.no/ident?v=2.6.0-test7&i=writeable
no hits.

http://lxr.linux.no/search?v=2.6.0-test7&string=writeable
over seventy hits.  Apparently none relevant, except to say scsi_scan
sets this bit for sd, clears this bit for sr, and sr sometimes sets and
fetches this bit until I patch sr to branch on CDC_MMC_WR instead.

Pat LaVarre