drm/rockchip: Clear all interrupts before requesting the IRQ

Calling request_irq() followed by disable_irq() is usually a bad idea,
specially if the interrupt can be pending, and you're not yet in a
position to handle it.

This is exactly what happens on my kevin system when rebooting in a
second kernel using kexec: Some interrupt is left pending from
the previous kernel, and we take it too early, before disable_irq()
could do anything.

Let's clear the pending interrupts as we initialize the HW, and move
the interrupt request after that point. This ensures that we're in
a sane state when the interrupt is requested.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[adapted to recent rockchip-drm changes]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180220130120.5254-2-marc.zyngier@arm.com
This commit is contained in:
Marc Zyngier 2018-02-20 13:01:18 +00:00 committed by Heiko Stuebner
parent ce31ddd5c4
commit 5f9e93fed4

View file

@ -1401,6 +1401,9 @@ static int vop_initial(struct vop *vop)
usleep_range(10, 20);
reset_control_deassert(ahb_rst);
VOP_INTR_SET_TYPE(vop, clear, INTR_MASK, 1);
VOP_INTR_SET_TYPE(vop, enable, INTR_MASK, 0);
memcpy(vop->regsbak, vop->regs, vop->len);
VOP_REG_SET(vop, misc, global_regdone_en, 1);
@ -1564,17 +1567,9 @@ static int vop_bind(struct device *dev, struct device *master, void *data)
spin_lock_init(&vop->irq_lock);
mutex_init(&vop->vop_lock);
ret = devm_request_irq(dev, vop->irq, vop_isr,
IRQF_SHARED, dev_name(dev), vop);
if (ret)
return ret;
/* IRQ is initially disabled; it gets enabled in power_on */
disable_irq(vop->irq);
ret = vop_create_crtc(vop);
if (ret)
goto err_enable_irq;
return ret;
pm_runtime_enable(&pdev->dev);
@ -1585,13 +1580,19 @@ static int vop_bind(struct device *dev, struct device *master, void *data)
goto err_disable_pm_runtime;
}
ret = devm_request_irq(dev, vop->irq, vop_isr,
IRQF_SHARED, dev_name(dev), vop);
if (ret)
goto err_disable_pm_runtime;
/* IRQ is initially disabled; it gets enabled in power_on */
disable_irq(vop->irq);
return 0;
err_disable_pm_runtime:
pm_runtime_disable(&pdev->dev);
vop_destroy_crtc(vop);
err_enable_irq:
enable_irq(vop->irq); /* To balance out the disable_irq above */
return ret;
}