Re: [PATCHv2] usb: gadget: f_fs: Add flags to descriptors block

[Manu Gautam <mgautam@codeaurora.org>]

On 2/25/2014 10:32 PM, Michal Nazarewicz wrote:
> This reworks the way SuperSpeed descriptors are added and instead of
> having a magick after full and high speed descriptors, it reworks the
> whole descriptors block to include a flags field which lists which
> descriptors are present and makes future extensions possible.
> 
> Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
> ---

> Manu, if you could include it in your series, adjust your user space
> client and test it, it would be wonderful. :]
> 

I have tested this with my userspace client. It works fine. I checked
both DESC_MAGIC and DESC_MAGIC_V2 with and without passing ss_descs.
I faced one issue when I was using MAGIC_V2 and specified ss_count as 0.
This resulted in driver treating ss_count as start of descs blob.
Later noticed that this is now changed and depending on the flags
(descriptors) passed, these fields may or may not be present. I see that
you have explicitly mentioned the same in functionfs.h. This looks fine
to me.
Additionally, there were could of typos (mentioned below) which I have
fixed in the patch.

>  
>  #define FUNCTIONFS_SS_DESC_MAGIC 0x0055DE5C

can be removed.

> + * |     | fs_count  | LE32         | number of full-speed descriptors     |
> + * |     | hs_count  | LE32         | number of high-speed descriptors     |
> + * |     | ss_count  | LE32         | number of high-speed descriptors     |

s/full/super

> + * |     | fs_descrs | Descriptor[] | list of full-speed descriptors       |
> + * |     | hs_descrs | Descriptor[] | list of high-speed descriptors       |
> + * |     | ss_descrs | Descriptor[] | list of high-speed descriptors       |

s/full/super

> + *
> + * Depending on which flags are set, various fields may be missing in the
> + * structure.  Any flags that are not recognised cause the whole block to be
> + * rejected with -ENOSYS.

This is what I was talking about.

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation