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From:   Ruslan Bilovol <ruslan.bilovol@gmail.com>
Date:   Tue, 3 Jul 2018 01:36:17 +0300
Message-ID: <CAB=otbQiUDtZBAn0RhtQsizqz-r0Do+8nd991rvE+DQv_71o0Q@mail.gmail.com>
Subject: Re: [PATCH] usb: gadget: f_uac2: fix endianness of 'struct cntrl_*_lay3'
To:     Eugeniu Rosca <roscaeugeniu@gmail.com>
Cc:     Felipe Balbi <balbi@kernel.org>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Vincent Pelletier <plr.vincent@gmail.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Eugeniu Rosca <erosca@de.adit-jv.com>,
        Eugeniu Rosca <rosca.eugeniu@gmail.com>
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On Tue, Jul 3, 2018 at 12:46 AM, Eugeniu Rosca <roscaeugeniu@gmail.com> wrote:
> The list [1] of commits doing endianness fixes in USB subsystem is long
> due to below quote from USB spec Revision 2.0 from April 27, 2000:
>
> ------------
> 8.1 Byte/Bit Ordering
>
> Multiple byte fields in standard descriptors, requests, and responses
> are interpreted as and moved over the bus in little-endian order, i.e.
> LSB to MSB.
> ------------
>
> This commit belongs to the same family.
>
> [1] Example of endianness fixes in USB subsystem:
> commit 14e1d56cbea6 ("usb: gadget: f_uac2: endianness fixes.")
> commit 42370b821168 ("usb: gadget: f_uac1: endianness fixes.")
> commit 63afd5cc7877 ("USB: chaoskey: fix Alea quirk on big-endian hosts")
> commit 74098c4ac782 ("usb: gadget: acm: fix endianness in notifications")
> commit cdd7928df0d2 ("ACM gadget: fix endianness in notifications")
> commit 323ece54e076 ("cdc-wdm: fix endianness bug in debug statements")
> commit e102609f1072 ("usb: gadget: uvc: Fix endianness mismatches")
>        list goes on
>
> Fixes: 132fcb460839 ("usb: gadget: Add Audio Class 2.0 Driver")
> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>

Good catch!

Reviewed-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>

> ---
>  drivers/usb/gadget/function/f_uac2.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
> index d2dc1f00180b..540a0ce63ad4 100644
> --- a/drivers/usb/gadget/function/f_uac2.c
> +++ b/drivers/usb/gadget/function/f_uac2.c
> @@ -438,14 +438,14 @@ static struct usb_descriptor_header *hs_audio_desc[] = {
>  };
>
>  struct cntrl_cur_lay3 {
> -       __u32   dCUR;
> +       __le32  dCUR;
>  };
>
>  struct cntrl_range_lay3 {
> -       __u16   wNumSubRanges;
> -       __u32   dMIN;
> -       __u32   dMAX;
> -       __u32   dRES;
> +       __le16  wNumSubRanges;
> +       __le32  dMIN;
> +       __le32  dMAX;
> +       __le32  dRES;
>  } __packed;
>
>  static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
> @@ -703,9 +703,9 @@ in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
>                 memset(&c, 0, sizeof(struct cntrl_cur_lay3));
>
>                 if (entity_id == USB_IN_CLK_ID)
> -                       c.dCUR = p_srate;
> +                       c.dCUR = cpu_to_le32(p_srate);
>                 else if (entity_id == USB_OUT_CLK_ID)
> -                       c.dCUR = c_srate;
> +                       c.dCUR = cpu_to_le32(c_srate);
>
>                 value = min_t(unsigned, w_length, sizeof c);
>                 memcpy(req->buf, &c, value);
> @@ -742,15 +742,15 @@ in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
>
>         if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
>                 if (entity_id == USB_IN_CLK_ID)
> -                       r.dMIN = p_srate;
> +                       r.dMIN = cpu_to_le32(p_srate);
>                 else if (entity_id == USB_OUT_CLK_ID)
> -                       r.dMIN = c_srate;
> +                       r.dMIN = cpu_to_le32(c_srate);
>                 else
>                         return -EOPNOTSUPP;
>
>                 r.dMAX = r.dMIN;
>                 r.dRES = 0;
> -               r.wNumSubRanges = 1;
> +               r.wNumSubRanges = cpu_to_le16(1);
>
>                 value = min_t(unsigned, w_length, sizeof r);
>                 memcpy(req->buf, &r, value);
> --
> 2.18.0
>