From: Mark yao <mark.yao@rock-chips.com>
To: Daniel Kurtz <djkurtz@chromium.org>
Cc: David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Rob Clark <robdclark@gmail.com>,
Philipp Zabel <p.zabel@pengutronix.de>,
dri-devel <dri-devel@lists.freedesktop.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"open list:ARM/Rockchip SoC..."
<linux-rockchip@lists.infradead.org>
Subject: Re: [PATCH] drm/rockchip: vop: power off until vop standby take effect
Date: Mon, 02 Feb 2015 10:30:09 +0800 [thread overview]
Message-ID: <54CEE131.1020600@rock-chips.com> (raw)
In-Reply-To: <CAGS+omA70JADHR3PhGq-qC8MYobQjsR91MLw6RXdQ6xag0UQWg@mail.gmail.com>
On 2015年02月02日 10:07, Daniel Kurtz wrote:
> Hi Mark, Heiko,
>
> On Sat, Jan 31, 2015 at 4:41 PM, Mark Yao <mark.yao@rock-chips.com> wrote:
>> Vop standby will take effect end of current frame,
>> if dsp_hold_valid_irq happen, it means vop standby complete.
>>
>> we must wait standby complete when we want to disable aclk,
>> if not, memory bus maybe dead.
>>
>> Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
>> ---
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 76 ++++++++++++++++++++++-----
>> 1 file changed, 63 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> index fb25836..47ea61f 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> @@ -89,6 +89,7 @@ struct vop {
>> /* mutex vsync_ work */
>> struct mutex vsync_mutex;
>> bool vsync_work_pending;
>> + struct completion dsp_hold_completion;
>>
>> const struct vop_data *data;
>>
>> @@ -382,6 +383,34 @@ static bool is_alpha_support(uint32_t format)
>> }
>> }
>>
>> +static void vop_dsp_hold_valid_irq_enable(struct vop *vop)
>> +{
>> + unsigned long flags;
>> +
>> + BUG_ON(!vop->is_enabled);
> Re: Heiko "use a WARN_ON":
>
> If the VOP clock is off, then the system will just hang when trying to
> write the VOP register so in this case, BUG_ON gives a more reliable
> crash dump than the hang.
In this way, you are right, if vop clocks is disabled, write vop
register will hang system, and the WARN_ON
crash dump may be have no chance to print.
>
>> +
>> + spin_lock_irqsave(&vop->irq_lock, flags);
>> +
>> + vop_mask_write(vop, INTR_CTRL0, DSP_HOLD_VALID_INTR_MASK,
>> + DSP_HOLD_VALID_INTR_EN(1));
>> +
>> + spin_unlock_irqrestore(&vop->irq_lock, flags);
>> +}
>> +
>> +static void vop_dsp_hold_valid_irq_disable(struct vop *vop)
>> +{
>> + unsigned long flags;
>> +
>> + BUG_ON(!vop->is_enabled);
>> +
>> + spin_lock_irqsave(&vop->irq_lock, flags);
>> +
>> + vop_mask_write(vop, INTR_CTRL0, DSP_HOLD_VALID_INTR_MASK,
>> + DSP_HOLD_VALID_INTR_EN(0));
>> +
>> + spin_unlock_irqrestore(&vop->irq_lock, flags);
>> +}
>> +
>> static void vop_enable(struct drm_crtc *crtc)
>> {
>> struct vop *vop = to_vop(crtc);
>> @@ -454,26 +483,36 @@ static void vop_disable(struct drm_crtc *crtc)
>>
>> drm_vblank_off(crtc->dev, vop->pipe);
>>
>> - disable_irq(vop->irq);
>> -
>> /*
>> - * TODO: Since standby doesn't take effect until the next vblank,
>> - * when we turn off dclk below, the vop is probably still active.
>> + * Vop standby will take effect until end of current frame,
> "Vop standby will take effect at end of current frame"
OK
>> + * if dsp hold valid irq happen, it means standby complete.
>> + *
>> + * we must wait standby complete when we want to disable aclk,
>> + * if not, memory bus maybe dead.
>> */
>> + reinit_completion(&vop->dsp_hold_completion);
>> + vop_dsp_hold_valid_irq_enable(vop);
>> +
>> spin_lock(&vop->reg_lock);
>>
>> VOP_CTRL_SET(vop, standby, 1);
>>
>> spin_unlock(&vop->reg_lock);
>>
>> + wait_for_completion(&vop->dsp_hold_completion);
>> +
>> + vop_dsp_hold_valid_irq_disable(vop);
>> +
>> + disable_irq(vop->irq);
>> +
>> vop->is_enabled = false;
>> +
>> /*
>> - * disable dclk to stop frame scan, so we can safely detach iommu,
>> + * vop standby complete, so iommu detach is safe.
>> */
>> - clk_disable(vop->dclk);
>> -
>> rockchip_drm_dma_detach_device(vop->drm_dev, vop->dev);
>>
>> + clk_disable(vop->dclk);
>> clk_disable(vop->aclk);
>> clk_disable(vop->hclk);
>> }
>> @@ -1086,6 +1125,7 @@ static irqreturn_t vop_isr(int irq, void *data)
>> struct vop *vop = data;
>> uint32_t intr0_reg, active_irqs;
>> unsigned long flags;
>> + int ret = IRQ_NONE;
>>
>> /*
>> * INTR_CTRL0 register has interrupt status, enable and clear bits, we
>> @@ -1104,15 +1144,24 @@ static irqreturn_t vop_isr(int irq, void *data)
>> if (!active_irqs)
>> return IRQ_NONE;
>>
>> - /* Only Frame Start Interrupt is enabled; other irqs are spurious. */
>> - if (!(active_irqs & FS_INTR)) {
>> - DRM_ERROR("Unknown VOP IRQs: %#02x\n", active_irqs);
>> - return IRQ_NONE;
>> + if (active_irqs & DSP_HOLD_VALID_INTR) {
>> + if (!completion_done(&vop->dsp_hold_completion))
> Why is this "completion_done" check needed?
> I guess it doesn't help, but isn't strictly needed, since the
> dsp_hold_completion is a one shot, right?
Right, the DSP_HOLD_VALID_INTR only happen when standby complete, one
standby one irq.
Mark
> In any case, this should work as it is, so:
>
> Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
>
>> + complete(&vop->dsp_hold_completion);
>> + active_irqs &= ~DSP_HOLD_VALID_INTR;
>> + ret = IRQ_HANDLED;
>> }
>>
>> - drm_handle_vblank(vop->drm_dev, vop->pipe);
>> + if (active_irqs & FS_INTR) {
>> + drm_handle_vblank(vop->drm_dev, vop->pipe);
>> + active_irqs &= ~FS_INTR;
>> + ret = (vop->vsync_work_pending) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
>> + }
>>
>> - return (vop->vsync_work_pending) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
>> + /* Unhandled irqs are spurious. */
>> + if (active_irqs)
>> + DRM_ERROR("Unknown VOP IRQs: %#02x\n", active_irqs);
>> +
>> + return ret;
>> }
>>
>> static int vop_create_crtc(struct vop *vop)
>> @@ -1194,6 +1243,7 @@ static int vop_create_crtc(struct vop *vop)
>> goto err_cleanup_crtc;
>> }
>>
>> + init_completion(&vop->dsp_hold_completion);
>> crtc->port = port;
>> vop->pipe = drm_crtc_index(crtc);
>> rockchip_register_crtc_funcs(drm_dev, &private_crtc_funcs, vop->pipe);
>> --
>> 1.7.9.5
>>
>>
>
>
next prev parent reply other threads:[~2015-02-02 2:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-31 8:41 [PATCH] drm/rockchip: vop: power off until vop standby take effect Mark Yao
2015-01-31 12:49 ` Heiko Stübner
2015-02-02 0:45 ` Mark yao
2015-02-02 2:07 ` Daniel Kurtz
2015-02-02 2:30 ` Mark yao [this message]
2015-02-02 7:53 ` Daniel Vetter
2015-02-04 3:38 ` Mark yao
2015-02-04 3:48 ` Daniel Kurtz
2015-02-04 3:56 ` Mark yao
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