Hello Alan > When you mount the USB drive, do you use the "-o sync" option? That could > cause the delays and the errors that you see. They are not caused by > problems in the 2.6.12 USB drivers. (Well, some of the delays are caused > by the driver -- but they wouldn't be there if no errors occurred.
No, i do not use any options when i mount the usb drive. I assume that the mount command do not use sync option by default. I am still facing USB hang issue and i did some debuggging and my obeservations are given below. 1.A file copy to USB hard disk results in drop in free memory. The free memory is consumed by kernel page cache and is not released. Note that my reference board has ONLY 32MB of SDRAM and free memory drops below 1Mb when USB file copy is in progress. 2.During the copy operation, the pdflush daemon gets triggerd(as seen by top) indicating the system is low on memory. Any attempts to do anothter copy to USB fails as kernel kills cp process due to OOM. Is there any way to instruct the kernel NOT to use page cache ? Any idea about why the page cache memory is not released ? what commands can be used to flush the page cache ? Regards Vivek -----Original Message----- From: Alan Stern [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 16, 2006 3:02 PM To: Vivek Dharmadhikari Cc: linux-usb-devel@lists.sourceforge.net Subject: Re: [linux-usb-devel] Usb hangs during small and large file transfer On Fri, 12 May 2006, Vivek Dharmadhikari wrote: > > Hello All > > I have ported linux 2.6.12 USB driver to 200MHz MIPS SOC with synopsys > USB 2.0 block. The USB block is NOT interfaced using PCI therefore I > used platform glue structure to port the driver. The driver is now > working. > > I am facing issues when using a 2.0 external HARD disk or flash drive. I > can copy small files(less than 500k) to and from the disk without any > issues. Large file transfer(greater than 1MByts)takes long time to > finish and as a result the console gets locked giving impression that > USB is hanging. Attempts to do file transfer larger than 50MBytes > results in bus reset message by the driver. During the file transfer > scsi_eh_0 and usb-storage alternates between S and D state as reported > by top command. The endpoints are halted and cleared during transfer as > is evident from dmesg below. ... > Is this a known issue in 2.6.12 series usb driver ? When you mount the USB drive, do you use the "-o sync" option? That could cause the delays and the errors that you see. They are not caused by problems in the 2.6.12 USB drivers. (Well, some of the delays are caused by the driver -- but they wouldn't be there if no errors occurred.) Alan Stern ------------------------------------------------------- All the advantages of Linux Managed Hosting--Without the Cost and Risk! Fully trained technicians. The highest number of Red Hat certifications in the hosting industry. Fanatical Support. Click to learn more http://sel.as-us.falkag.net/sel?cmd=lnk&kid7521&bid$8729&dat1642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
