On Thu, 27 Nov 2003, Ian Molton wrote:

> Hi
> 
> I just bought a 'Super Talent Inc.' 64MB flash 'key'. (supposedly USB2.0)
> 
> Reads are 'fast enough' but writes are *dire* taking very nearly an *hour* to write 
> 64MB of data.
> 
> the data appears to have written ok, just slowly.
> 
> the USB ID is 067b:2517 and there is a controller chip and two samsung flash chips 
> inside
> 
> Controller has markings:
> PL-2515
> 03272D
> 
> Flash chips are:
> SAMSUNG: K9F5608UDC-YCB0
> 
> the card has been tried on 2.4.20 (i686) and 2.6.0-test9 (i686)
> 
> on 2.4.20 it was under the usb-uhci driver
> on 2.6.0-test9 it was under the ohci/ehci drivers.
> 
> output from /proc/bus/usb/devices shows it has some kind of 'embedded hub' whatever 
> thats used for.
> 
> T:  Bus=01 Lev=01 Prnt=01 Port=02 Cnt=01 Dev#=  2 Spd=480 MxCh= 1
> D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
> P:  Vendor=067b ProdID=2515 Rev= 0.01
> S:  Manufacturer=Super Talent Flash Inc.
> S:  Product=USB Embedded Hub
> C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=100mA
> I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
> E:  Ad=81(I) Atr=03(Int.) MxPS=   1 Ivl=256ms
>  
> T:  Bus=01 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#=  3 Spd=480 MxCh= 0
> D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
> P:  Vendor=067b ProdID=2517 Rev= 0.01
> S:  Manufacturer=Super Talent Flash Inc.
> S:  Product=USB Mass Storage Device
> C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=  0mA
> I:  If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=05 Prot=50 Driver=usb-storage
> E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms

Usually when things go very slowly, like your writes, it's because there's 
some recurring error.  Error recovery can take a lot of time; it totally 
ruins your throughput.

To try and track this down, you can configure your kernel to turn on
usb-storage debugging and make sure your syslog daemon is set to capture
all kernel debugging messages.  Warning: this will generate some pretty
big log files, as usb-storage debugging is very verbose.  Try setting that
up and run through your test, then post the debugging output in the kernel
log.

Alan Stern



-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
Does SourceForge.net help you be more productive?  Does it
help you create better code?  SHARE THE LOVE, and help us help
YOU!  Click Here: http://sourceforge.net/donate/
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel

Reply via email to