On Fri, 2004-02-06 at 09:59, Alan Stern wrote: > Who says it's wrong to retrieve sense information when there is an > underrun but not Check Condition? Can you provide a reference to a > published (or draft) document that states this?
It's not wrong according to the SCSI standards, a REQUEST SENSE issued to a device with no sense data will produce a NO SENSE key. However, because of the way sense is processed in contingent allegiance conditions (suspending the I_T_L nexus until sense is cleared) it is dangerous to issue arbitrary request sense commands because you may receive sense for a different command (and prevent that command from erroring correctly). The SCSI mid-layer definitely does not expect this behaviour. A driver either does not do any sense commands at all or it only issues a REQUEST SENSE in response to a Check Condition status in order not to have the nexus halted because of a contingent allegiance condition (simulating ACA if you will). James ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
