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 :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html