target/linux/brcm2708/patches-4.4/0094-drm-vc4-Use-job_lock-to-protect-seqno_cb_list.patch

   1 From cfa018eec8227589076e45fd65f654e525349ff5 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Mon, 19 Oct 2015 08:32:24 -0700
   4 Subject: [PATCH] drm/vc4: Use job_lock to protect seqno_cb_list.
   5
   6 We're (mostly) not supposed to be using struct_mutex in drivers these
   7 days.
   8
   9 Signed-off-by: Eric Anholt <eric@anholt.net>
  10 ---
  11  drivers/gpu/drm/vc4/vc4_gem.c | 8 +++++---
  12  1 file changed, 5 insertions(+), 3 deletions(-)
  13
  14 --- a/drivers/gpu/drm/vc4/vc4_gem.c
  15 +++ b/drivers/gpu/drm/vc4/vc4_gem.c
  16 @@ -474,7 +474,6 @@ vc4_job_handle_completed(struct vc4_dev
  17                 vc4_complete_exec(exec);
  18                 spin_lock_irqsave(&vc4->job_lock, irqflags);
  19         }
  20 -       spin_unlock_irqrestore(&vc4->job_lock, irqflags);
  21
  22         list_for_each_entry_safe(cb, cb_temp, &vc4->seqno_cb_list, work.entry) {
  23                 if (cb->seqno <= vc4->finished_seqno) {
  24 @@ -482,6 +481,8 @@ vc4_job_handle_completed(struct vc4_dev
  25                         schedule_work(&cb->work);
  26                 }
  27         }
  28 +
  29 +       spin_unlock_irqrestore(&vc4->job_lock, irqflags);
  30  }
  31
  32  static void vc4_seqno_cb_work(struct work_struct *work)
  33 @@ -496,18 +497,19 @@ int vc4_queue_seqno_cb(struct drm_device
  34  {
  35         struct vc4_dev *vc4 = to_vc4_dev(dev);
  36         int ret = 0;
  37 +       unsigned long irqflags;
  38
  39         cb->func = func;
  40         INIT_WORK(&cb->work, vc4_seqno_cb_work);
  41
  42 -       mutex_lock(&dev->struct_mutex);
  43 +       spin_lock_irqsave(&vc4->job_lock, irqflags);
  44         if (seqno > vc4->finished_seqno) {
  45                 cb->seqno = seqno;
  46                 list_add_tail(&cb->work.entry, &vc4->seqno_cb_list);
  47         } else {
  48                 schedule_work(&cb->work);
  49         }
  50 -       mutex_unlock(&dev->struct_mutex);
  51 +       spin_unlock_irqrestore(&vc4->job_lock, irqflags);
  52
  53         return ret;
  54  }