From ef8be75663178c0720d0944d9305f624776fc91c Mon Sep 17 00:00:00 2001 From: Sandor Yu Date: Thu, 17 Oct 2019 16:29:49 +0800 Subject: [PATCH] drm: mhdp: add mutex lock to mhdp register access function Add muxtex lock to mhdp registers access functions that could avoid race condition between cec thread and hdmi video. Signed-off-by: Sandor Yu --- drivers/gpu/drm/bridge/cadence/cdns-dp-core.c | 1 + drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c | 1 + drivers/gpu/drm/bridge/cadence/cdns-mhdp-common.c | 8 ++++++++ include/drm/bridge/cdns-mhdp-common.h | 1 + 4 files changed, 11 insertions(+) --- a/drivers/gpu/drm/bridge/cadence/cdns-dp-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dp-core.c @@ -410,6 +410,7 @@ static int __cdns_dp_probe(struct platfo int ret; mutex_init(&mhdp->lock); + mutex_init(&mhdp->iolock); INIT_DELAYED_WORK(&mhdp->hotplug_work, hotplug_work_func); --- a/drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c @@ -411,6 +411,7 @@ static int __cdns_hdmi_probe(struct plat int ret; mutex_init(&mhdp->lock); + mutex_init(&mhdp->iolock); INIT_DELAYED_WORK(&mhdp->hotplug_work, hotplug_work_func); --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp-common.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-common.c @@ -75,6 +75,8 @@ u32 cdns_mhdp_bus_read(struct cdns_mhdp_ { u32 val; + mutex_lock(&mhdp->iolock); + if (mhdp->bus_type == BUS_TYPE_LOW4K_SAPB) { /* Remap address to low 4K SAPB bus */ writel(offset >> 12, mhdp->regs_sec + 0xc); @@ -88,12 +90,16 @@ u32 cdns_mhdp_bus_read(struct cdns_mhdp_ else val = readl(mhdp->regs_base + offset); + mutex_unlock(&mhdp->iolock); + return val; } EXPORT_SYMBOL(cdns_mhdp_bus_read); void cdns_mhdp_bus_write(u32 val, struct cdns_mhdp_device *mhdp, u32 offset) { + mutex_lock(&mhdp->iolock); + if (mhdp->bus_type == BUS_TYPE_LOW4K_SAPB) { /* Remap address to low 4K SAPB bus */ writel(offset >> 12, mhdp->regs_sec + 0xc); @@ -106,6 +112,8 @@ void cdns_mhdp_bus_write(u32 val, struct writel(val, mhdp->regs_sec + offset); else writel(val, mhdp->regs_base + offset); + + mutex_unlock(&mhdp->iolock); } EXPORT_SYMBOL(cdns_mhdp_bus_write); --- a/include/drm/bridge/cdns-mhdp-common.h +++ b/include/drm/bridge/cdns-mhdp-common.h @@ -685,6 +685,7 @@ struct cdns_mhdp_device { bool plugged; bool is_hpd; struct mutex lock; + struct mutex iolock; int irq[IRQ_NUM];