sr_scsi_status SENSE_NOTREADY

Thread View: comp.sys.next.programmer

1 messages

[T] Back to Threads [V] Tree View [G] Group Articles

1 total messages Started by Terry Gliedt Mon, 14 Sep 1992 13:15

#1020

Author: Terry Gliedt
Date: Mon, 14 Sep 1992 13:15

15 lines
1466 bytes

I have a driver for a SCSI-attached Epson 300C scanner working pretty well. The
code drives the scanner using /dev/sg0 using ioctl (opcodes C6OP_READ and
C6OP-WRITE). After much experimentation it appears there is a maximum number
of bytes of 256 I can read. When I issue an ioctl-read for > 256 bytes, I get a
error in sr_io_status (01x) and a sr_scsi_status of SENSE_NOTREADY.

Initially I tried to simply wait a little and retry, but I never get any other
status. I've tried clearing the attention with a sense and retry, but to no
avail. I have tried to break the read into several reads, but this too failed.
There is clearly something I do not understand and so far am unable to guess.
Everything works fine as along as the scanner generates <= 240 bytes per scan
line. As soon as the scanner tries to return > 240 bytes (I think the magic 
number of 256), the SENSE_NOTREADY begins to appear.

I'd appreciate some advice from you ioctl-gurus. Thanks!

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads