Re: [PATCH 3/3] usb: gadget: mass_storage: add documentation

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On Mon, 11 Jun 2012, Michal Nazarewicz wrote:
+  Mass Storage Gadget (or MSG) acts as a USB Mass Storage device,
+  appearing to the host as a disk or a CD-ROM drive.  It supports
+  multiple logical units (LUNs).  Backing storage for each LUN is
+  provided by a regular file or a block device, access can be limited
+  to read-only, and gadget can indicate that it is removable and/or
+  CD-ROM (the latter implies read-only access).

On Mon, 11 Jun 2012 17:25:15 +0200, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
Does CD-ROM really imply read-only?  If not, shouldn't it?

It indeed does:

		curlun->ro = lcfg->cdrom || lcfg->ro;

+  - ro=b[,b...]
+    This parameter specifies whether each logical unit should be
+    reported as read only.  This will prevent host from modifying the
+    backing files.
+    Note that if this flag for given logical unit is false but the
+    backing file could not be opened in read/write mode, the gadget
+    will fall back to read only mode anyway.
+    The default value for each logical unit is false.

Shouldn't the default be true for logical units that are cdroms?

Indeed.  I've changed this last line to: The default value for non-CD-ROM
logical units is false; for logical units simulating CD-ROM it is forced
to true.

Very good.  When you make the small changes listed above, you can add

Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

I'll resend it tomorrow in case anyone else has any comments.

Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--
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