Re: [PATCH] cdrom sane fallback vs 2.4.20-pre1

[Erik Andersen <andersen@codepoet.org>]

On Mon Aug 12, 2002 at 11:58:26PM -0300, Marcelo Tosatti wrote:
> 
> 
> On Sun, 11 Aug 2002, Erik Andersen wrote:
> 
> > --- drivers/cdrom/cdrom.c~	Sun Aug 11 15:37:20 2002
> > +++ drivers/cdrom/cdrom.c	Sun Aug 11 15:37:24 2002
> > @@ -1916,6 +1916,7 @@
> >  {
> >  	struct cdrom_device_ops *cdo = cdi->ops;
> >  	struct cdrom_generic_command cgc;
> > +	struct request_sense sense;
> >  	kdev_t dev = cdi->dev;
> >  	char buffer[32];
> >  	int ret = 0;
> > @@ -1951,9 +1952,11 @@
> >  		cgc.buffer = (char *) kmalloc(blocksize, GFP_KERNEL);
> >  		if (cgc.buffer == NULL)
> >  			return -ENOMEM;
> > +		memset(&sense, 0, sizeof(sense));
> > +		cgc.sense = &sense;
> >  		cgc.data_direction = CGC_DATA_READ;
> >  		ret = cdrom_read_block(cdi, &cgc, lba, 1, format, blocksize);
> > -		if (ret) {
> > +		if (ret && sense.sense_key==0x05 && sense.asc==0x20 && sense.ascq==0x00) {
> 
> Do you really need to hardcode this values ?

This allows it to falls back to READ_10 only when the drive
reports "Hey! You gave me an invalid command!" which is the one
and only case when a fall back to READ_10 is appropriate.  I am
not aware of any other reason for which a fallback to READ_10 is
useful.

 -Erik

--
Erik B. Andersen             http://codepoet-consulting.com/
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