On Wed, Apr 29, 2015 at 05:51:44PM +0200, Greg KH wrote: > On Wed, Apr 29, 2015 at 10:25:22AM -0500, Felipe Balbi wrote: > > Hi, > > > > On Wed, Apr 29, 2015 at 07:37:34PM +0800, Xuebing Wang wrote: > > > Hi Community, > > > > > > I am developing a commercial product based on Freescale iMX6, which supports > > > USB slave Mass Storage, command is: > > > modprobe g_mass_storage file=/dev/mmcblk0p4 > > > > > > (it is one partition in eMMC, this partition is formatted as FAT32) > > > (kernel version is 3.10.17, I did not try the latest mainline kernel) > > > > well, with such an old kernel, you're really on your own. > > > > > When connect device to Windows 7 host, performance is slow, it takes > > > 1.5 minutes to copy a 180MB file to mass storage slave. > > > > so here it takes 1.5 minutes. > > > > > But, on MacOS, it takes less than 15 minutes to copy the same 180MB > > > file. > > > > and here it takes 15 minutes ? IMO, your problem is with Mac OS X, not > > windows. > > > > > Did anyone experience the same issue? > > > > > > If this is still a known issue, I'd like to give this a try to improve > > > mass storage performance when connecting to Windows host. > > > > try setting nofua parameter. Windows always sets FUA bit (so all writes > > are *always* flushed to non-volatile media), but telling mass storage > > gadget to ignore FUA bit, you get better performance. > > At the expense of possibly loosing your data if you loose power, so > ignore it at your own peril :) Well, unless you're completely powered via USB and have no batteries, then yeah, you have an issue. The likelyhood that you have batteries is much, much larger, though. cheers -- balbi
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