Marek, I've been working with Jim on this.
The latest u-boot code we tried (2012.07) does seem to be much faster WRT reading ext volumes from USB media. We were still able to eke out a bit more speed by removing the Test Unit Ready calls per Read/Write. In my experience, you only call Test Unit Ready during initialization of a device (e.g., SCSI) or after device reset. We still haven't heard a reason why it is being done for each Read and Write operation. Was it put in to work around bad hardware? Thanks, Steve Heckman On Sun, Aug 12, 2012 at 7:54 PM, Marek Vasut <ma...@denx.de> wrote: > Dear Jim Shimer, > > > While tuning ext2load, we found that usb_test_unit_ready was being called > > every block read. We compared the usb block storage to the scsi block > > storage cmd_scsi.c, and found that the scsi device was only calling its > > scsi_setup_test_unit_ready() during scsi_can. It appears that > > usb_test_unit_ready() really only needs to be called once during > > usb_stor_scan(), via usb_stor_get_info(). Is there a particular reason > > usb_test_unit_ready is called for every block read, or do you think its > ok > > to only call during usb_stor_scan()? We're finding this speeds up > ext2load > > quite a bit. > > Jim, did we get anywhere on this one ? Can you try with the new ext4 code > in > Wolfgangs' u-boot-master/ext4 branch? > > > Regards, > > Jim > > Best regards, > Marek Vasut >
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