Netbooks & BSD

[Polytropon]

On Wed, 20 Oct 2010 14:54:21 -0700, David Brodbeck <gull at gull.us> wrote:
> Fortunately, USB mass storage devices are highly standardized.  One of
> the things they got right.

Highly, but not fully. In some cases, manufacturers "know better"
and produce memory sticks that don't work on FreeBSD as they do
require some "driver" (no idea what is meant) to be accessible.
They seem to vialote the standards for USB direct access, so the
system gets into trouble (because it has to work with an obviously
defective storage media).

Here's an example of a stick I returned to the shop the same day,
said "It's broken, money back." with a dmesg + fdisk printout on
tractor paper (always looks impressive). :-)

umass0: <SanDisk Cruzer Micro, class 0/0, rev 2.00/2.00, addr 2> on uhub2
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <SanDisk Cruzer Micro 8.02> Removable Direct Access SCSI-0 device 
da0: 40.000MB/s transfers
da0: Attempt to query device size failed: UNIT ATTENTION, Medium not present
umass0: at uhub2 port 2 (addr 2) disconnected
(da0:umass-sim0:0:0:0): lost device
(da0:umass-sim0:0:0:0): removing device entry
umass0: detached

I couldn't not format it (it was some FAT format on it) as it
detached from the system by itself as soon as accessed.



> Now, the USB keyboard protocol...ugh, they really dropped the ball on
> that one.  It's standardized, which is good, but it's a polling
> interface and tends to occasionally lose events under high CPU load,
> which is bad.  Especially if it's a key-up event that gets lost.

USB mice suffer from the same problem - the polling. In the past,
I never had problems with interrupt-driven (serial and PS/2)
equipment, even on lowest-end (!) hardware. Today, some load can
render the system nearly inresponsive for several seconds (no
keyboard input, mouse stopped).




-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...