target/linux/bcm27xx/patches-5.4/950-0949-media-dvbsky-use-a-single-mutex-and-state-buffers-fo.patch

   1 From 08ccbb8e0667e90e5c7334057965c6205a3855fb Mon Sep 17 00:00:00 2001
   2 From: Andrei Koshkosh <andreykosh000@mail.ru>
   3 Date: Sun, 29 Sep 2019 05:04:05 -0300
   4 Subject: [PATCH] media: dvbsky: use a single mutex and state buffers
   5  for all R/W ops
   6
   7 commit cecf0bbbcb6f035a5ca2197f3e11ec2b7fb3da83 upstream.
   8
   9 Re-use usb_mutex from dvb_usb_device for this.
  10
  11 See: https://github.com/raspberrypi/linux/issues/3809
  12
  13 Tested-by: Jan Pieter van Woerkom <jp@jpvw.nl>
  14 Signed-off-by: Andrei Koshkosh <andreykosh000@mail.ru>
  15 Signed-off-by: Sean Young <sean@mess.org>
  16 Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
  17 ---
  18  drivers/media/usb/dvb-usb-v2/dvbsky.c | 16 ++++++++--------
  19  1 file changed, 8 insertions(+), 8 deletions(-)
  20
  21 --- a/drivers/media/usb/dvb-usb-v2/dvbsky.c
  22 +++ b/drivers/media/usb/dvb-usb-v2/dvbsky.c
  23 @@ -22,7 +22,6 @@ MODULE_PARM_DESC(disable_rc, "Disable in
  24  DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
  25
  26  struct dvbsky_state {
  27 -       struct mutex stream_mutex;
  28         u8 ibuf[DVBSKY_BUF_LEN];
  29         u8 obuf[DVBSKY_BUF_LEN];
  30         u8 last_lock;
  31 @@ -60,17 +59,19 @@ static int dvbsky_usb_generic_rw(struct
  32  static int dvbsky_stream_ctrl(struct dvb_usb_device *d, u8 onoff)
  33  {
  34         struct dvbsky_state *state = d_to_priv(d);
  35 +       static const u8 obuf_pre[3] = { 0x37, 0, 0 };
  36 +       static const u8 obuf_post[3] = { 0x36, 3, 0 };
  37         int ret;
  38 -       u8 obuf_pre[3] = { 0x37, 0, 0 };
  39 -       u8 obuf_post[3] = { 0x36, 3, 0 };
  40
  41 -       mutex_lock(&state->stream_mutex);
  42 -       ret = dvbsky_usb_generic_rw(d, obuf_pre, 3, NULL, 0);
  43 +       mutex_lock(&d->usb_mutex);
  44 +       memcpy(state->obuf, obuf_pre, 3);
  45 +       ret = dvb_usbv2_generic_write_locked(d, state->obuf, 3);
  46         if (!ret && onoff) {
  47                 msleep(20);
  48 -               ret = dvbsky_usb_generic_rw(d, obuf_post, 3, NULL, 0);
  49 +               memcpy(state->obuf, obuf_post, 3);
  50 +               ret = dvb_usbv2_generic_write_locked(d, state->obuf, 3);
  51         }
  52 -       mutex_unlock(&state->stream_mutex);
  53 +       mutex_unlock(&d->usb_mutex);
  54         return ret;
  55  }
  56
  57 @@ -598,7 +599,6 @@ static int dvbsky_init(struct dvb_usb_de
  58         if (ret)
  59                 return ret;
  60         */
  61 -       mutex_init(&state->stream_mutex);
  62
  63         state->last_lock = 0;
  64