On Tue, 29 Jun 2010, Subs wrote: > On Tue, Jun 29, 2010 at 12:25 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, 28 Jun 2010, Subs wrote: > > > >> Hi All, > >> > >> In my class driver I am receiving data transfer buffer as number of > >> Scatter-Gather lists from SCSI layer to perform data transfers. > >> > >> Is there any alternate way to get the transfer buffer from SCSI other > >> than SG. I wanted to receive the complete data transfer buffer as a > >> single pointer. > > > > As far as I know, there is no alternate way to get the transfer buffer > > from the SCSI layer. > > > > However you can get the effect you want by setting the sg_tablesize > > field in your scsi_host_template to 1. > > > > Just out of curiosity, why are you writing a class driver for the BOT > > class? Aren't the two existing drivers in the kernel good enough? > > > > Alan Stern > > > > > > By changing sg_tablesize to 1, there is no change in number of buffers > that I am receiving in SG list. Then you must be doing something wrong. I just tried changing sg_tablesize in the usb-storage driver, and as a result the scatterlists it received contained only one element. (Of course, in usb-storage what matters is not the value in the scsi_host_template but rather the value returned by usb_stor_sg_tablesize.) > > Just out of curiosity, why are you writing a class driver for the BOT > > class? Aren't the two existing drivers in the kernel good enough? > > I am writing my custom class driver, which can do Control and Bulk > transfers only. This is nowhere related to Mass Storage BOT transfers. Then why did you mention BOT in the email Subject: line? Does it refer to something other than Bulk-Only-Transport? Alan Stern -- 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
