usb/95173: [umass] [patch] cannot mount external usb harddisk VIA Technologies Inc. USB 2.0 IDE Bridge

[Ben Kelly]

The following reply was made to PR usb/95173; it has been noted by GNATS.

From: Ben Kelly <bkelly at vadev.org>
To: bug-followup at FreeBSD.org, diazepam at gmx.net
Cc:  
Subject: Re: usb/95173: [umass] [patch] cannot mount external usb harddisk VIA Technologies Inc. USB 2.0 IDE Bridge
Date: Sat, 26 Jan 2008 14:14:16 -0500

 For the PR I thought I would also just throw in another thought I  
 had.  It occurred to me that since umass devices are usually designed  
 for a "can be pulled at any time" environment, it seems likely that  
 most of them disable write caching anyways.
 
 With that in mind, would it make more sense to disable the SYNC  
 command by default and add a quirk for those devices where its known  
 to be functioning and useful?
 
 This might increase the default compatibility of the FreeBSD USB stack  
 with devices in the future.  I count around 34 entries in scsi_da.c  
 for umass devices simply to add the NO_SYNC quirk.
 
 Just a thought.  If people are interested I can develop a patch for  
 this.