Alan Stern,您好！
thank you!
due to my nand flash driver accessing speed is very slow,only 700KB/s
when copying form flash to flash ,
the linux system filesystem cached increased too large to response the UFI
test_unit_ready or write command in time.
so ,Windows indicates the timeout error and my usb device driver failed
to recover from this error.
I want to know how to tell windows that the device can only process 700KB/s
data ,and send data less or equal to this length to device.
btw,do anyone know how to flush the write-behind buffer to nand flash ?
======= 2006-10-08 23:47:48 您在来信中写道：=======
>On Sun, 8 Oct 2006, JackRain wrote:
>
>> linux-usb-users，您好！
>>
>> I have a question about the host/device disagreement on data
>> transfer stage:
>>
>> 1/ the usb device is capable to receive ,saying 8192 Bytes data ,and
>> process it (writing to nand flash ),
>> but host is indicating 65536 Bytes /*(cmd[7] < < 8) | cmd[8])
>> *BLOCK_SIZE */ to send to device.
>>
>> how can I balance the speed difference between host and device ?
>> I want the usb device finish processing the received data
>>
>> before the host send out data ,so that device can handle the
>> incoming data and won't cause a TIMEOUT reset.
>
>You don't have to do anything. The host will wait for the device to be
>ready. The timeout period is very long, several seconds. The device
>certainly ought to be able to write a few KB to flash in one second.
>
>> 2/ when copy a little several MB file to U-disk,it won't crash ,and
>> very fast,the speed is up to 780KB/s in Full-speed.
>>
>> right now,my usb device driver will crash if repeat copy & delete
>> the file on the U-disk or copy a huge file to U-disk from PC.
>
>It sounds like there's a bug in your device driver.
>
>> I found the system memory is very low after this operation,from 18MB
>> to 370KB.
>>
>> someone told me that it is caused by the filesystem cache which
>> too much data in ,but can't write to nand flash inmediately.
>
>What is your question?
>
>Alan Stern
>
= = = = = = = = = = = = = = = = = = = =
致
礼！
JackRain
[EMAIL PROTECTED]
2006-10-10
-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Linux-usb-users@lists.sourceforge.net
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-users
