On Wed, 2010-02-17 at 18:07 +0530, Ramya Desai wrote: > What is the number of maximum sectors that SCSI can send to MS driver > in a single data transfer? I have no idea what the MS driver is, so it's impossible to answer specifically. Generically, for drivers that expect a contiguous sg list, then 128 elements (512k) is the maximum. For drivers updated to use the sg chaining API (which is at least all of those in drivers/scsi), there is no maximum except what the hardware is limited to. > I changed the max_sectors in struct scsi_host_template > usb_stor_host_template structure to 2048. Still, SCSI is sending 1024 > sectors (512 KB) in a single data transfer. > I know that my device supports 1 MB data in a sigle transfer. How can > I change this to 1 MB? As long as the driver supports chaining, you increase it in /sys/block/dev>/queue/max_sectors_kb. For compatibility reasons this stays clamped at 512 unless a user specifically raises it. James -- 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
