hi Bryn: 2014-07-07 17:20 GMT+08:00 Bryn M. Reeves <bmr@xxxxxxxxxx>: > On Sun, Jul 06, 2014 at 01:18:03AM +0800, loody wrote: >> hi all: >> we met a USB Hard Disk that will go to suspend if host stop >> sending scsi command over 5mins. >> To save the IO, kernel will keep the file in page cache as much as >> he can and under this circumstances, the scsi command may disappear >> for a while longer enough to cause the device suspend. >> >> is there any kernel config or module parameter can do the dummy >> read or scsi command periodically? > > No but you could set up a simple cron job to call an sg3_utils command. > > E.g. issue an sg_read for one sector to the device every 4m: > > */4 * * * * sg_read count=1 if=/dev/<disk> Since my target platform arm embedded system, does that mean I should include sg_read in my Busybox or cross-compile sg_read from sg3_utils? appreciate your kind help, -- 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
