releases/4.6.1/mei-amthif-discard-not-read-messages.patch

   1 From 9d04ee11db7bf0d848266cbfd7db336097a0e239 Mon Sep 17 00:00:00 2001
   2 From: Alexander Usyskin <alexander.usyskin@intel.com>
   3 Date: Sun, 17 Apr 2016 12:16:04 -0400
   4 Subject: mei: amthif: discard not read messages
   5
   6 From: Alexander Usyskin <alexander.usyskin@intel.com>
   7
   8 commit 9d04ee11db7bf0d848266cbfd7db336097a0e239 upstream.
   9
  10 When a message is received and amthif client is not in reading state
  11 the message is ignored and left dangling in the queue. This may happen
  12 after one of the amthif host connections is closed w/o completing the
  13 reading. Another client will pick up a wrong message on next read
  14 attempt which will lead to link reset.
  15 To prevent this the driver has to properly discard the message when
  16 amthif client is not in reading state.
  17
  18 Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
  19 Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21
  22 ---
  23  drivers/misc/mei/amthif.c    |    4 +++-
  24  drivers/misc/mei/interrupt.c |    1 -
  25  drivers/misc/mei/mei_dev.h   |    2 ++
  26  3 files changed, 5 insertions(+), 2 deletions(-)
  27
  28 --- a/drivers/misc/mei/amthif.c
  29 +++ b/drivers/misc/mei/amthif.c
  30 @@ -380,8 +380,10 @@ int mei_amthif_irq_read_msg(struct mei_c
  31
  32         dev = cl->dev;
  33
  34 -       if (dev->iamthif_state != MEI_IAMTHIF_READING)
  35 +       if (dev->iamthif_state != MEI_IAMTHIF_READING) {
  36 +               mei_irq_discard_msg(dev, mei_hdr);
  37                 return 0;
  38 +       }
  39
  40         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
  41         if (ret)
  42 --- a/drivers/misc/mei/interrupt.c
  43 +++ b/drivers/misc/mei/interrupt.c
  44 @@ -76,7 +76,6 @@ static inline int mei_cl_hbm_equal(struc
  45   * @dev: mei device
  46   * @hdr: message header
  47   */
  48 -static inline
  49  void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
  50  {
  51         /*
  52 --- a/drivers/misc/mei/mei_dev.h
  53 +++ b/drivers/misc/mei/mei_dev.h
  54 @@ -704,6 +704,8 @@ bool mei_hbuf_acquire(struct mei_device
  55
  56  bool mei_write_is_idle(struct mei_device *dev);
  57
  58 +void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr);
  59 +
  60  #if IS_ENABLED(CONFIG_DEBUG_FS)
  61  int mei_dbgfs_register(struct mei_device *dev, const char *name);
  62  void mei_dbgfs_deregister(struct mei_device *dev);