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From: James Bottomley <James.Bottomley@suse.de>
To: Ramya Desai <ramya.desai@gmail.com>
Cc: USB list <linux-usb@vger.kernel.org>,
	linux-scsi@vger.kernel.org, Greg KH <greg@kroah.com>,
	Alan Stern <stern@rowland.harvard.edu>
Subject: Re: Maximum data size in a single transfer for MS driver
Date: Thu, 18 Feb 2010 09:47:29 -0600	[thread overview]
Message-ID: <1266508049.4355.37.camel@mulgrave.site> (raw)
In-Reply-To: <3e7aae31002180046i771f2e1encfcda864f564c87e@mail.gmail.com>

On Thu, 2010-02-18 at 14:16 +0530, Ramya Desai wrote:
> On Wed, Feb 17, 2010 at 8:32 PM, James Bottomley
> <James.Bottomley@suse.de> wrote:
> 
> > I have no idea what the MS driver is, so it's impossible to answer
> > specifically.
> 
> MS means mass storage driver only.

OK, still don't know what that is ... but Randy decoded this for me; he
said you mean a driver under drivers/usb/storage?  

In that case, it looks like the helpers in protocol.c do use chaining
correctly (as long as the driver isn't doing direct dma), but there's a
clamp on the sg table size in scsiglue.c:

.sg_tablesize = SG_ALL

That would have to be changed to SCSI_MAX_SG_CHAIN_SEGMENTS to enable
chaining.

James



  reply	other threads:[~2010-02-18 15:47 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-17 12:37 Maximum data size in a single transfer for MS driver Ramya Desai
     [not found] ` <3e7aae31002170437i52ba4ba1w10c1ff224d9b37ef-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-02-17 15:02   ` James Bottomley
2010-02-18  8:46     ` Ramya Desai
2010-02-18 15:47       ` James Bottomley [this message]
     [not found]         ` <1266508049.4355.37.camel-0iu6Cu4xQGLYCGPCin2YbQ@public.gmane.org>
2010-02-18 16:24           ` Alan Stern
     [not found]             ` <Pine.LNX.4.44L0.1002181115120.1294-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-18 16:30               ` James Bottomley
     [not found]                 ` <1266510627.4355.41.camel-0iu6Cu4xQGLYCGPCin2YbQ@public.gmane.org>
2010-02-18 16:51                   ` Alan Stern
2010-02-19 12:43         ` Ramya Desai
2010-02-19 14:26           ` James Bottomley
2010-02-22 12:50             ` Ramya Desai
     [not found]               ` <3e7aae31002220450o6f83d2f3n45c795d70ef01f72-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-02-22 13:06                 ` James Bottomley
2010-02-22 14:15                   ` Ramya Desai
2010-02-22 17:44                   ` Alan Stern
2010-02-22 18:07                     ` Alan Stern
     [not found]                     ` <Pine.LNX.4.44L0.1002221232160.1251-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-23 15:29                       ` Ramya Desai
2010-02-23 16:49                         ` Alan Stern
2010-02-23 17:00                           ` Martin K. Petersen
2010-02-23 18:01                             ` Alan Stern
     [not found]                               ` <Pine.LNX.4.44L0.1002231253320.1308-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-24 13:07                                 ` Ramya Desai
2010-02-24 13:12                                   ` Jens Axboe
2010-02-24 16:30                                   ` Alan Stern
2010-02-24 19:07                                     ` Jens Axboe
2010-02-25 14:47                                       ` Ramya Desai
2010-02-25 14:44                                     ` Ramya Desai
2010-02-25 16:37                             ` Alan Stern
2010-02-25 16:49                               ` Martin K. Petersen
2010-02-25 16:53                                 ` Martin K. Petersen
2010-02-25 17:54                                   ` Jens Axboe
     [not found]                                   ` <yq1zl2xl0j3.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2010-02-25 18:28                                     ` Alan Stern
2010-02-25 19:05                                       ` Martin K. Petersen
     [not found]                                         ` <yq1iq9lkueh.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2010-02-25 19:47                                           ` Alan Stern
2010-02-26  3:37                                             ` Martin K. Petersen
     [not found]                               ` <Pine.LNX.4.44L0.1002251132170.1686-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-25 17:52                                 ` Jens Axboe
  -- strict thread matches above, loose matches on Subject: below --
2010-02-25 16:59 scameron
2010-02-25 17:00 ` scameron
2010-02-25 17:18 ` scameron
2010-02-25 17:28   ` Martin K. Petersen
2010-02-25 17:41     ` Boaz Harrosh
2010-02-25 17:58       ` Martin K. Petersen
2010-02-25 19:07       ` Martin K. Petersen

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