diff mbox

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

Message ID xa1tob1vazxh.fsf@mina86.com (mailing list archive)
State New, archived
Headers show

Commit Message

Michał Nazarewicz Feb. 25, 2014, 5:02 p.m. UTC
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>
---
 drivers/usb/gadget/f_fs.c           | 136 +++++++++++++++---------------------
 drivers/usb/gadget/u_fs.h           |  12 ++--
 include/uapi/linux/usb/functionfs.h |  49 ++++++++-----
 3 files changed, 94 insertions(+), 103 deletions(-)

All right, with some fidling with my fan and limiting CPU frequency to
the mininimum, I've managed to compile this patch and fixed all the
typos.

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

Comments

Felipe Balbi Feb. 25, 2014, 6:32 p.m. UTC | #1
Hi,

On Tue, Feb 25, 2014 at 06:02:18PM +0100, 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>
> ---
>  drivers/usb/gadget/f_fs.c           | 136 +++++++++++++++---------------------
>  drivers/usb/gadget/u_fs.h           |  12 ++--
>  include/uapi/linux/usb/functionfs.h |  49 ++++++++-----
>  3 files changed, 94 insertions(+), 103 deletions(-)
> 
> All right, with some fidling with my fan and limiting CPU frequency to
> the mininimum, I've managed to compile this patch and fixed all the
> typos.
> 
> Manu, if you could include it in your series, adjust your user space
> client and test it, it would be wonderful. :]

I'll wait for that then. Note that I want to close my tree next
wednesday tops.
Manu Gautam Feb. 28, 2014, 10:11 a.m. UTC | #2
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.
Krzysztof Opasiak June 4, 2014, 2:24 p.m. UTC | #3
Hello Michal,

> -----Original Message-----
> From: linux-usb-owner@vger.kernel.org [mailto:linux-usb-
> owner@vger.kernel.org] On Behalf Of Michal Nazarewicz
> Sent: Tuesday, February 25, 2014 6:02 PM
> To: Manu Gautam
> Cc: balbi@ti.com; jackp@codeaurora.org; pheatwol@codeaurora.org;
> linux-usb@vger.kernel.org; linux-arm-msm@vger.kernel.org;
> benoit@android.com; Andrzej Pietrasiewicz;
> gregkh@linuxfoundation.org; Manu Gautam
> Subject: [PATCHv2] usb: gadget: f_fs: Add flags to descriptors
> block
> 
> 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>
> ---
>  drivers/usb/gadget/f_fs.c           | 136 +++++++++++++++---------
> ------------
>  drivers/usb/gadget/u_fs.h           |  12 ++--
>  include/uapi/linux/usb/functionfs.h |  49 ++++++++-----
>  3 files changed, 94 insertions(+), 103 deletions(-)
> 
> All right, with some fidling with my fan and limiting CPU frequency
> to
> the mininimum, I've managed to compile this patch and fixed all the
> typos.
> 
> Manu, if you could include it in your series, adjust your user
> space
> client and test it, it would be wonderful. :]
> 

(...) snip

> diff --git a/include/uapi/linux/usb/functionfs.h
> b/include/uapi/linux/usb/functionfs.h
> index 0f8f7be..ee6fcbc 100644
> --- a/include/uapi/linux/usb/functionfs.h
> +++ b/include/uapi/linux/usb/functionfs.h
> @@ -10,7 +10,14 @@
> 
>  enum {
>  	FUNCTIONFS_DESCRIPTORS_MAGIC = 1,
> -	FUNCTIONFS_STRINGS_MAGIC     = 2
> +	FUNCTIONFS_STRINGS_MAGIC = 2,
> +	FUNCTIONFS_DESCRIPTORS_MAGIC_V2 = 3,
> +};
> +
> +enum functionfs_flags {
> +	FUNCTIONFS_HAS_FS_DESC = 1,
> +	FUNCTIONFS_HAS_HS_DESC = 2,
> +	FUNCTIONFS_HAS_SS_DESC = 4,
>  };
> 
>  #define FUNCTIONFS_SS_DESC_MAGIC 0x0055DE5C
> @@ -30,33 +37,39 @@ struct usb_endpoint_descriptor_no_audio {
> 
> 
>  /*
> - * All numbers must be in little endian order.
> - */
> -
> -struct usb_functionfs_descs_head {
> -	__le32 magic;
> -	__le32 length;
> -	__le32 fs_count;
> -	__le32 hs_count;
> -} __attribute__((packed));
> -
> -/*

I have tried to compile FFS examples with v3.15-rc8 but I have faced an
issue that they are unable to build due to missing definition of this
structure. The same is with adb, sdb and all userspace apps which use
legacy API. What is the reason of removing it? Was your intentions?

Maybe would be a good idea to leave this structure untouched as legacy
userspace API?

There is also no structure definition for new API, maybe suitable
structure should be defined (struct usb_functionfs_descs_head2 for
example) to make userspace life easier?


--
BR's
Krzysztof Opasiak
Samsung R&D Institute Poland
Samsung Electronics
k.opasiak@samsung.com




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Michał Nazarewicz June 4, 2014, 7:06 p.m. UTC | #4
>> -struct usb_functionfs_descs_head {
>> -	__le32 magic;
>> -	__le32 length;
>> -	__le32 fs_count;
>> -	__le32 hs_count;
>> -} __attribute__((packed));

On Wed, Jun 04 2014, Krzysztof Opasiak <k.opasiak@samsung.com> wrote:
> I have tried to compile FFS examples with v3.15-rc8 but I have faced an
> issue that they are unable to build due to missing definition of this
> structure.

https://lkml.org/lkml/2014/5/21/522

> The same is with adb, sdb and all userspace apps which use legacy
> API. What is the reason of removing it? Was your intentions?

It was a mistake on my part.

> Maybe would be a good idea to leave this structure untouched as legacy
> userspace API?

I don't care either way to be honest.  I guess if there's non-negligible
number of usb_functionfs_descs_head structure users out there, I can
prepare a CL adding the structure back.

> There is also no structure definition for new API, maybe suitable
> structure should be defined (struct usb_functionfs_descs_head2 for
> example) to make userspace life easier?

That structure would not have many fields though, since what exactly the
header contains depends on the flags.  Whether fs_count, hs_count and
ss_count fields are present depends on which bits in the flags are set.
So the usb_functionfs_descs_head2 structure could only contain:

	struct usb_functionfs_descs_head2 {
		__le32 magic;
		__le32 length;
		__le32 flags;
	};

I'm not sure if that would be particularly helpful.
Krzysztof Opasiak June 5, 2014, 11:32 a.m. UTC | #5
Hi,

> -----Original Message-----
> From: Michal Nazarewicz [mailto:mpn@google.com] On Behalf Of Michal
> Nazarewicz
> Sent: Wednesday, June 04, 2014 9:06 PM
> To: Krzysztof Opasiak; 'Manu Gautam'
> Cc: balbi@ti.com; jackp@codeaurora.org; pheatwol@codeaurora.org;
> linux-usb@vger.kernel.org; linux-arm-msm@vger.kernel.org;
> benoit@android.com; Andrzej Pietrasiewicz;
> gregkh@linuxfoundation.org; 'Manu Gautam'; Karol Lewandowski; Marek
> Szyprowski
> Subject: Re: [PATCHv2] usb: gadget: f_fs: Add flags to descriptors
> block
> 
> >> -struct usb_functionfs_descs_head {
> >> -	__le32 magic;
> >> -	__le32 length;
> >> -	__le32 fs_count;
> >> -	__le32 hs_count;
> >> -} __attribute__((packed));
> 
> On Wed, Jun 04 2014, Krzysztof Opasiak <k.opasiak@samsung.com>
> wrote:
> > I have tried to compile FFS examples with v3.15-rc8 but I have
> faced an
> > issue that they are unable to build due to missing definition of
> this
> > structure.
> 
> https://lkml.org/lkml/2014/5/21/522

Thank you for this link, I have missed that patch.

> I don't care either way to be honest.  I guess if there's non-
> negligible
> number of usb_functionfs_descs_head structure users out there, I
> can
> prepare a CL adding the structure back.

The number of FFS users which I know is limited to 3 maybe 4, so it's not too much. I can port all of them to new API but I'm not sure if we would like to do this?

> 
> > There is also no structure definition for new API, maybe suitable
> > structure should be defined (struct usb_functionfs_descs_head2
> for
> > example) to make userspace life easier?
> 
> That structure would not have many fields though, since what
> exactly the
> header contains depends on the flags.  Whether fs_count, hs_count
> and
> ss_count fields are present depends on which bits in the flags are
> set.
> So the usb_functionfs_descs_head2 structure could only contain:
> 
> 	struct usb_functionfs_descs_head2 {
> 		__le32 magic;
> 		__le32 length;
> 		__le32 flags;
> 	};
> 
> I'm not sure if that would be particularly helpful.

I think that this structure is much more user friendly than copy-paste of those 3 fields in each ffs program.
diff mbox

Patch

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 928959d..fab63d3 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -1167,7 +1167,7 @@  static void ffs_data_clear(struct ffs_data *ffs)
 	if (ffs->epfiles)
 		ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
 
-	kfree(ffs->raw_descs);
+	kfree(ffs->raw_descs_data);
 	kfree(ffs->raw_strings);
 	kfree(ffs->stringtabs);
 }
@@ -1179,12 +1179,12 @@  static void ffs_data_reset(struct ffs_data *ffs)
 	ffs_data_clear(ffs);
 
 	ffs->epfiles = NULL;
+	ffs->raw_descs_data = NULL;
 	ffs->raw_descs = NULL;
 	ffs->raw_strings = NULL;
 	ffs->stringtabs = NULL;
 
-	ffs->raw_fs_hs_descs_length = 0;
-	ffs->raw_ss_descs_length = 0;
+	ffs->raw_descs_length = 0;
 	ffs->fs_descs_count = 0;
 	ffs->hs_descs_count = 0;
 	ffs->ss_descs_count = 0;
@@ -1598,89 +1598,76 @@  static int __ffs_data_do_entity(enum ffs_entity_type type,
 static int __ffs_data_got_descs(struct ffs_data *ffs,
 				char *const _data, size_t len)
 {
-	unsigned fs_count, hs_count, ss_count = 0;
-	int fs_len, hs_len, ss_len, ret = -EINVAL;
-	char *data = _data;
+	char *data = _data, *raw_descs;
+	unsigned counts[3], flags;
+	int ret = -EINVAL, i;
 
 	ENTER();
 
-	if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
-		     get_unaligned_le32(data + 4) != len))
+	if (get_unaligned_le32(data + 4) != len)
 		goto error;
-	fs_count = get_unaligned_le32(data +  8);
-	hs_count = get_unaligned_le32(data + 12);
-
-	data += 16;
-	len  -= 16;
 
-	if (likely(fs_count)) {
-		fs_len = ffs_do_descs(fs_count, data, len,
-				      __ffs_data_do_entity, ffs);
-		if (unlikely(fs_len < 0)) {
-			ret = fs_len;
+	switch (get_unaligned_le32(data)) {
+	case FUNCTIONFS_DESCRIPTORS_MAGIC:
+		flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
+		data += 8;
+		len  -= 8;
+		break;
+	case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
+		flags = get_unaligned_le32(data + 8);
+		if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
+			      FUNCTIONFS_HAS_HS_DESC |
+			      FUNCTIONFS_HAS_SS_DESC)) {
+			ret = -ENOSYS;
 			goto error;
 		}
-
-		data += fs_len;
-		len  -= fs_len;
-	} else {
-		fs_len = 0;
+		data += 12;
+		len  -= 12;
+		break;
+	default:
+		goto error;
 	}
 
-	if (likely(hs_count)) {
-		hs_len = ffs_do_descs(hs_count, data, len,
-				   __ffs_data_do_entity, ffs);
-		if (unlikely(hs_len < 0)) {
-			ret = hs_len;
+	/* Read fs_count, hs_count and ss_count (if present) */
+	for (i = 0; i < 3; ++i) {
+		if (!(flags & (1 << i))) {
+			counts[i] = 0;
+		} else if (len < 4) {
 			goto error;
+		} else {
+			counts[i] = get_unaligned_le32(data);
+			data += 4;
+			len  -= 4;
 		}
-
-		data += hs_len;
-		len  -= hs_len;
-	} else {
-		hs_len = 0;
 	}
 
-	if (len >= 8) {
-		/* Check SS_MAGIC for presence of ss_descs and get SS_COUNT */
-		if (get_unaligned_le32(data) != FUNCTIONFS_SS_DESC_MAGIC)
-			goto einval;
-
-		ss_count = get_unaligned_le32(data + 4);
-		data += 8;
-		len  -= 8;
-	}
-
-	if (!fs_count && !hs_count && !ss_count)
-		goto einval;
-
-	if (ss_count) {
-		ss_len = ffs_do_descs(ss_count, data, len,
+	/* Read descriptors */
+	raw_descs = data;
+	for (i = 0; i < 3; ++i) {
+		if (!counts[i])
+			continue;
+		ret = ffs_do_descs(counts[i], data, len,
 				   __ffs_data_do_entity, ffs);
-		if (unlikely(ss_len < 0)) {
-			ret = ss_len;
+		if (ret < 0)
 			goto error;
-		}
-		ret = ss_len;
-	} else {
-		ss_len = 0;
-		ret = 0;
+		data += ret;
+		len  -= ret;
 	}
 
-	if (unlikely(len != ret))
-		goto einval;
+	if (raw_descs == data || len) {
+		ret = -EINVAL;
+		goto error;
+	}
 
-	ffs->raw_fs_hs_descs_length	 = fs_len + hs_len;
-	ffs->raw_ss_descs_length	 = ss_len;
-	ffs->raw_descs			 = _data;
-	ffs->fs_descs_count		 = fs_count;
-	ffs->hs_descs_count		 = hs_count;
-	ffs->ss_descs_count		 = ss_count;
+	ffs->raw_descs_data	= _data;
+	ffs->raw_descs		= raw_descs;
+	ffs->raw_descs_length	= data - raw_descs;
+	ffs->fs_descs_count	= counts[0];
+	ffs->hs_descs_count	= counts[1];
+	ffs->ss_descs_count	= counts[2];
 
 	return 0;
 
-einval:
-	ret = -EINVAL;
 error:
 	kfree(_data);
 	return ret;
@@ -2092,8 +2079,7 @@  static int _ffs_func_bind(struct usb_configuration *c,
 	vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
 		super ? ffs->ss_descs_count + 1 : 0);
 	vla_item_with_sz(d, short, inums, ffs->interfaces_count);
-	vla_item_with_sz(d, char, raw_descs,
-			ffs->raw_fs_hs_descs_length + ffs->raw_ss_descs_length);
+	vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
 	char *vlabuf;
 
 	ENTER();
@@ -2109,15 +2095,9 @@  static int _ffs_func_bind(struct usb_configuration *c,
 
 	/* Zero */
 	memset(vla_ptr(vlabuf, d, eps), 0, d_eps__sz);
-	/* Copy only raw (hs,fs) descriptors (until ss_magic and ss_count) */
-	memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs + 16,
-		ffs->raw_fs_hs_descs_length);
-	/* Copy SS descs present @ header + hs_fs_descs + ss_magic + ss_count */
-	if (func->ffs->ss_descs_count)
-		memcpy(vla_ptr(vlabuf, d, raw_descs) +
-				ffs->raw_fs_hs_descs_length,
-		       ffs->raw_descs + 16 + ffs->raw_fs_hs_descs_length + 8,
-		       ffs->raw_ss_descs_length);
+	/* Copy descriptors  */
+	memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
+	       ffs->raw_descs_length);
 
 	memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
 	for (ret = ffs->eps_count; ret; --ret) {
@@ -2599,7 +2579,7 @@  static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
 	existing = _ffs_find_dev(name);
 	if (existing)
 		return -EBUSY;
-	
+
 	dev->name = name;
 
 	return 0;
@@ -2682,7 +2662,7 @@  static void ffs_release_dev(struct ffs_data *ffs_data)
 	ffs_dev = ffs_data->private_data;
 	if (ffs_dev)
 		ffs_dev->mounted = false;
-	
+
 	if (ffs_dev->ffs_release_dev_callback)
 		ffs_dev->ffs_release_dev_callback(ffs_dev);
 
diff --git a/drivers/usb/gadget/u_fs.h b/drivers/usb/gadget/u_fs.h
index 08bf26e..46ddda9 100644
--- a/drivers/usb/gadget/u_fs.h
+++ b/drivers/usb/gadget/u_fs.h
@@ -210,15 +210,13 @@  struct ffs_data {
 
 	/* filled by __ffs_data_got_descs() */
 	/*
-	 * Real descriptors are 16 bytes after raw_descs (so you need
-	 * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
-	 * first full speed descriptor).
-	 * raw_fs_hs_descs_length does not have those 16 bytes added.
-	 * ss_descs are 8 bytes (ss_magic + count) pass the hs_descs
+	 * raw_descs is what you kfree, real_descs points inside of raw_descs,
+	 * where full speed, high speed and super speed descriptors start.
+	 * real_descs_length is the length of all those descriptors.
 	 */
+	const void			*raw_descs_data;
 	const void			*raw_descs;
-	unsigned			raw_fs_hs_descs_length;
-	unsigned			raw_ss_descs_length;
+	unsigned			raw_descs_length;
 	unsigned			fs_descs_count;
 	unsigned			hs_descs_count;
 	unsigned			ss_descs_count;
diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h
index 0f8f7be..ee6fcbc 100644
--- a/include/uapi/linux/usb/functionfs.h
+++ b/include/uapi/linux/usb/functionfs.h
@@ -10,7 +10,14 @@ 
 
 enum {
 	FUNCTIONFS_DESCRIPTORS_MAGIC = 1,
-	FUNCTIONFS_STRINGS_MAGIC     = 2
+	FUNCTIONFS_STRINGS_MAGIC = 2,
+	FUNCTIONFS_DESCRIPTORS_MAGIC_V2 = 3,
+};
+
+enum functionfs_flags {
+	FUNCTIONFS_HAS_FS_DESC = 1,
+	FUNCTIONFS_HAS_HS_DESC = 2,
+	FUNCTIONFS_HAS_SS_DESC = 4,
 };
 
 #define FUNCTIONFS_SS_DESC_MAGIC 0x0055DE5C
@@ -30,33 +37,39 @@  struct usb_endpoint_descriptor_no_audio {
 
 
 /*
- * All numbers must be in little endian order.
- */
-
-struct usb_functionfs_descs_head {
-	__le32 magic;
-	__le32 length;
-	__le32 fs_count;
-	__le32 hs_count;
-} __attribute__((packed));
-
-/*
  * Descriptors format:
  *
  * | off | name      | type         | description                          |
  * |-----+-----------+--------------+--------------------------------------|
- * |   0 | magic     | LE32         | FUNCTIONFS_{FS,HS}_DESCRIPTORS_MAGIC |
+ * |   0 | magic     | LE32         | FUNCTIONFS_DESCRIPTORS_MAGIC_V2      |
+ * |   4 | length    | LE32         | length of the whole data chunk       |
+ * |   8 | flags     | LE32         | combination of functionfs_flags      |
+ * |     | fs_count  | LE32         | number of full-speed descriptors     |
+ * |     | hs_count  | LE32         | number of high-speed descriptors     |
+ * |     | ss_count  | LE32         | number of high-speed descriptors     |
+ * |     | fs_descrs | Descriptor[] | list of full-speed descriptors       |
+ * |     | hs_descrs | Descriptor[] | list of high-speed descriptors       |
+ * |     | ss_descrs | Descriptor[] | list of high-speed descriptors       |
+ *
+ * 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.
+ *
+ * Legacy descriptors format:
+ *
+ * | off | name      | type         | description                          |
+ * |-----+-----------+--------------+--------------------------------------|
+ * |   0 | magic     | LE32         | FUNCTIONFS_DESCRIPTORS_MAGIC         |
  * |   4 | length    | LE32         | length of the whole data chunk       |
  * |   8 | fs_count  | LE32         | number of full-speed descriptors     |
  * |  12 | hs_count  | LE32         | number of high-speed descriptors     |
  * |  16 | fs_descrs | Descriptor[] | list of full-speed descriptors       |
  * |     | hs_descrs | Descriptor[] | list of high-speed descriptors       |
- * |     | ss_magic  | LE32         | FUNCTIONFS_SS_DESC_MAGIC             |
- * |     | ss_count  | LE32         | number of super-speed descriptors    |
- * |     | ss_descrs | Descriptor[] | list of super-speed descriptors      |
  *
- * ss_magic: if present then it implies that SS_DESCs are also present
- * descs are just valid USB descriptors and have the following format:
+ * All numbers must be in little endian order.
+ *
+ * Descriptor[] is an array of valid USB descriptors which have the following
+ * format:
  *
  * | off | name            | type | description              |
  * |-----+-----------------+------+--------------------------|