target/linux/layerscape/patches-5.4/805-display-0022-drm-mhdp-add-mutex-lock-to-mhdp-register-access-func.patch

   1 From ef8be75663178c0720d0944d9305f624776fc91c Mon Sep 17 00:00:00 2001
   2 From: Sandor Yu <Sandor.yu@nxp.com>
   3 Date: Thu, 17 Oct 2019 16:29:49 +0800
   4 Subject: [PATCH] drm: mhdp: add mutex lock to mhdp register access function
   5
   6 Add muxtex lock to mhdp registers access functions
   7 that could avoid race condition between cec thread and hdmi video.
   8
   9 Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
  10 ---
  11  drivers/gpu/drm/bridge/cadence/cdns-dp-core.c     | 1 +
  12  drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c   | 1 +
  13  drivers/gpu/drm/bridge/cadence/cdns-mhdp-common.c | 8 ++++++++
  14  include/drm/bridge/cdns-mhdp-common.h             | 1 +
  15  4 files changed, 11 insertions(+)
  16
  17 --- a/drivers/gpu/drm/bridge/cadence/cdns-dp-core.c
  18 +++ b/drivers/gpu/drm/bridge/cadence/cdns-dp-core.c
  19 @@ -410,6 +410,7 @@ static int __cdns_dp_probe(struct platfo
  20         int ret;
  21
  22         mutex_init(&mhdp->lock);
  23 +       mutex_init(&mhdp->iolock);
  24
  25         INIT_DELAYED_WORK(&mhdp->hotplug_work, hotplug_work_func);
  26
  27 --- a/drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c
  28 +++ b/drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c
  29 @@ -411,6 +411,7 @@ static int __cdns_hdmi_probe(struct plat
  30         int ret;
  31
  32         mutex_init(&mhdp->lock);
  33 +       mutex_init(&mhdp->iolock);
  34
  35         INIT_DELAYED_WORK(&mhdp->hotplug_work, hotplug_work_func);
  36
  37 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp-common.c
  38 +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-common.c
  39 @@ -75,6 +75,8 @@ u32 cdns_mhdp_bus_read(struct cdns_mhdp_
  40  {
  41         u32 val;
  42
  43 +       mutex_lock(&mhdp->iolock);
  44 +
  45         if (mhdp->bus_type == BUS_TYPE_LOW4K_SAPB) {
  46                 /* Remap address to low 4K SAPB bus */
  47                 writel(offset >> 12, mhdp->regs_sec + 0xc);
  48 @@ -88,12 +90,16 @@ u32 cdns_mhdp_bus_read(struct cdns_mhdp_
  49         else
  50                 val = readl(mhdp->regs_base + offset);
  51
  52 +       mutex_unlock(&mhdp->iolock);
  53 +
  54         return val;
  55  }
  56  EXPORT_SYMBOL(cdns_mhdp_bus_read);
  57
  58  void cdns_mhdp_bus_write(u32 val, struct cdns_mhdp_device *mhdp, u32 offset)
  59  {
  60 +       mutex_lock(&mhdp->iolock);
  61 +
  62         if (mhdp->bus_type == BUS_TYPE_LOW4K_SAPB) {
  63                 /* Remap address to low 4K SAPB bus */
  64                 writel(offset >> 12, mhdp->regs_sec + 0xc);
  65 @@ -106,6 +112,8 @@ void cdns_mhdp_bus_write(u32 val, struct
  66                 writel(val, mhdp->regs_sec + offset);
  67         else
  68                 writel(val, mhdp->regs_base + offset);
  69 +
  70 +       mutex_unlock(&mhdp->iolock);
  71  }
  72  EXPORT_SYMBOL(cdns_mhdp_bus_write);
  73
  74 --- a/include/drm/bridge/cdns-mhdp-common.h
  75 +++ b/include/drm/bridge/cdns-mhdp-common.h
  76 @@ -685,6 +685,7 @@ struct cdns_mhdp_device {
  77         bool plugged;
  78         bool is_hpd;
  79         struct mutex lock;
  80 +       struct mutex iolock;
  81
  82         int irq[IRQ_NUM];
  83