Re: [PATCH] cdrom: longer timeout for "Read Track Info" command

Jens Axboe
2007-01-02T13:50:59Z

On Tue, Jan 02 2007, Alan wrote:
> On Mon, 1 Jan 2007 18:36:24 -0800
> Jeremy Higdon <jeremy@sgi.com> wrote:
>
> > I have a DVD combo drive and a CD in which the
> > "READ TRACK INFORMATION" command (implemented in the
> > cdrom_get_track_info() function) takes about 7 seconds to run.
> > The current implementation of cdrom_get_track_info() uses the
> > default timeout of 5 seconds. So here's a patch that increases
> > the timeout from 5 to 15 seconds.
> >
> > The drive in question is a TSSTcorpCD/DVDW SN-S082D, and I have
> > a Silicon Image 680A adapter, in case that's of interest.
> >
> > signed-off-by: <jeremy@sgi.com>
>
> Please test with a seven second timeout rather than fifteen which is way
> longer than anyone wants to wait. Seven is the magic value used by
> another major vendor so ought to be right for all hardware 8)

Yep, I suspect this patch is long overdue. Jeremy, is this enough to fix
it for you?

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 66d028d..3105ddd 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -337,6 +337,12 @@ static const char *mrw_address_space[] = { "DMA", "GAA" };
/* used in the audio ioctls */
#define CHECKAUDIO if ((ret=check_for_audio_disc(cdi, cdo))) return ret

+/*
+ * Another popular OS uses 7 seconds as the hard timeout for default
+ * commands, so it is a good choice for us as well.
+ */
+#define CDROM_DEF_TIMEOUT (7 * HZ)
+
/* Not-exported routines. */
static int open_for_data(struct cdrom_device_info * cdi);
static int check_for_audio_disc(struct cdrom_device_info * cdi,
@@ -1528,7 +1534,7 @@ void init_cdrom_command(struct packet_command *cgc, void *buf, int len,
cgc->buffer = (char *) buf;
cgc->buflen = len;
cgc->data_direction = type;
- cgc->timeout = 5*HZ;
+ cgc->timeout = CDROM_DEF_TIMEOUT;
}

/* DVD handling */

--
Jens Axboe