From: Sandy Huang hjc@rock-chips.com
The vop irq is shared between vop and iommu and irq probing in the iommu driver moved to the probe function recently. This can in some cases lead to a stall if the irq is triggered while the vop driver still has it disabled, but the vop irq handler gets called.
But there is no real need to disable the irq, as the vop can simply also track its enabled state and ignore irqs in that case. For this we can simply check the power-domain state of the vop, similar to how the iommu driver does it.
So remove the enable/disable handling and add appropriate condition to the irq handler.
changes in v2: - move to just check the power-domain state - add clock handling changes in v3: - clarify comment to speak of runtime-pm not power-domain
Fixes: d0b912bd4c23 ("iommu/rockchip: Request irqs in rk_iommu_probe()") Cc: stable@vger.kernel.org Signed-off-by: Sandy Huang hjc@rock-chips.com Signed-off-by: Heiko Stuebner heiko@sntech.de Tested-by: Ezequiel Garcia ezequiel@collabora.com --- drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 28 ++++++++++++++------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index 9a1f272e41c7..ae8a69793aed 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -573,8 +573,6 @@ static int vop_enable(struct drm_crtc *crtc)
spin_unlock(&vop->reg_lock);
- enable_irq(vop->irq); - drm_crtc_vblank_on(crtc);
return 0; @@ -618,8 +616,6 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
vop_dsp_hold_valid_irq_disable(vop);
- disable_irq(vop->irq); - vop->is_enabled = false;
/* @@ -1195,6 +1191,16 @@ static irqreturn_t vop_isr(int irq, void *data) uint32_t active_irqs; int ret = IRQ_NONE;
+ /* + * The irq is shared with the iommu. If the runtime-pm state of the + * vop-device is disabled the irq has to be targetted at the iommu. + */ + if (!pm_runtime_get_if_in_use(vop->dev)) + return IRQ_NONE; + + if (WARN_ON(vop_core_clks_enable(vop))) + goto out; + /* * interrupt register has interrupt status, enable and clear bits, we * must hold irq_lock to avoid a race with enable/disable_vblank(). @@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data) spin_unlock(&vop->irq_lock);
/* This is expected for vop iommu irqs, since the irq is shared */ - if (!active_irqs) - return IRQ_NONE; + if (!active_irqs) { + ret = IRQ_NONE; + vop_core_clks_disable(vop); + goto out; + }
if (active_irqs & DSP_HOLD_VALID_INTR) { complete(&vop->dsp_hold_completion); @@ -1236,6 +1245,10 @@ static irqreturn_t vop_isr(int irq, void *data) DRM_DEV_ERROR(vop->dev, "Unknown VOP IRQs: %#02x\n", active_irqs);
+ vop_core_clks_disable(vop); + +out: + pm_runtime_put(vop->dev); return ret; }
@@ -1614,9 +1627,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data) 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:
Hi Heiko,
On 12/06/18 13:15, Heiko Stuebner wrote:
From: Sandy Huang hjc@rock-chips.com
The vop irq is shared between vop and iommu and irq probing in the iommu driver moved to the probe function recently. This can in some cases lead to a stall if the irq is triggered while the vop driver still has it disabled, but the vop irq handler gets called.
But there is no real need to disable the irq, as the vop can simply also track its enabled state and ignore irqs in that case. For this we can simply check the power-domain state of the vop, similar to how the iommu driver does it.
So remove the enable/disable handling and add appropriate condition to the irq handler.
changes in v2:
- move to just check the power-domain state
- add clock handling
changes in v3:
- clarify comment to speak of runtime-pm not power-domain
Fixes: d0b912bd4c23 ("iommu/rockchip: Request irqs in rk_iommu_probe()") Cc: stable@vger.kernel.org Signed-off-by: Sandy Huang hjc@rock-chips.com Signed-off-by: Heiko Stuebner heiko@sntech.de Tested-by: Ezequiel Garcia ezequiel@collabora.com
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 28 ++++++++++++++------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index 9a1f272e41c7..ae8a69793aed 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -573,8 +573,6 @@ static int vop_enable(struct drm_crtc *crtc) spin_unlock(&vop->reg_lock);
- enable_irq(vop->irq);
- drm_crtc_vblank_on(crtc);
return 0; @@ -618,8 +616,6 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc, vop_dsp_hold_valid_irq_disable(vop);
- disable_irq(vop->irq);
- vop->is_enabled = false;
/* @@ -1195,6 +1191,16 @@ static irqreturn_t vop_isr(int irq, void *data) uint32_t active_irqs; int ret = IRQ_NONE;
- /*
* The irq is shared with the iommu. If the runtime-pm state of the* vop-device is disabled the irq has to be targetted at the iommu.*/- if (!pm_runtime_get_if_in_use(vop->dev))
return IRQ_NONE;- if (WARN_ON(vop_core_clks_enable(vop)))
goto out;
As I mentioned before, a WARN_ON() in an interrupt handler is a good way to make a bad problem even worse, and will give information (full register and stack dump) that is mostly useless to the context at hand. Turning it to a dev_warn_ratelimited() (or DRM_ERROR_RATELIMITED if you want to be DRM compliant) would be a better approach, IMHO.
- /*
- interrupt register has interrupt status, enable and clear bits, we
- must hold irq_lock to avoid a race with enable/disable_vblank().
@@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data) spin_unlock(&vop->irq_lock); /* This is expected for vop iommu irqs, since the irq is shared */
- if (!active_irqs)
return IRQ_NONE;
- if (!active_irqs) {
ret = IRQ_NONE;vop_core_clks_disable(vop);goto out;- }
A couple of nits: ret is already set to IRQ_NONE at this stage, and you could simply rewrite it as:
if (!active_irq) goto out_disable;
if (active_irqs & DSP_HOLD_VALID_INTR) { complete(&vop->dsp_hold_completion); @@ -1236,6 +1245,10 @@ static irqreturn_t vop_isr(int irq, void *data) DRM_DEV_ERROR(vop->dev, "Unknown VOP IRQs: %#02x\n", active_irqs);
with the "out_disable" label placed here.
- vop_core_clks_disable(vop);
+out:
- pm_runtime_put(vop->dev); return ret;
} @@ -1614,9 +1627,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data) 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:
Thanks,
M.
Am Dienstag, 12. Juni 2018, 14:39:03 CEST schrieb Marc Zyngier:
Hi Heiko,
On 12/06/18 13:15, Heiko Stuebner wrote:
From: Sandy Huang hjc@rock-chips.com
The vop irq is shared between vop and iommu and irq probing in the iommu driver moved to the probe function recently. This can in some cases lead to a stall if the irq is triggered while the vop driver still has it disabled, but the vop irq handler gets called.
But there is no real need to disable the irq, as the vop can simply also track its enabled state and ignore irqs in that case. For this we can simply check the power-domain state of the vop, similar to how the iommu driver does it.
So remove the enable/disable handling and add appropriate condition to the irq handler.
changes in v2:
- move to just check the power-domain state
- add clock handling
changes in v3:
- clarify comment to speak of runtime-pm not power-domain
Fixes: d0b912bd4c23 ("iommu/rockchip: Request irqs in rk_iommu_probe()") Cc: stable@vger.kernel.org Signed-off-by: Sandy Huang hjc@rock-chips.com Signed-off-by: Heiko Stuebner heiko@sntech.de Tested-by: Ezequiel Garcia ezequiel@collabora.com
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 28 ++++++++++++++------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index 9a1f272e41c7..ae8a69793aed 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -573,8 +573,6 @@ static int vop_enable(struct drm_crtc *crtc) spin_unlock(&vop->reg_lock);
- enable_irq(vop->irq);
- drm_crtc_vblank_on(crtc);
return 0; @@ -618,8 +616,6 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc, vop_dsp_hold_valid_irq_disable(vop);
- disable_irq(vop->irq);
- vop->is_enabled = false;
/* @@ -1195,6 +1191,16 @@ static irqreturn_t vop_isr(int irq, void *data) uint32_t active_irqs; int ret = IRQ_NONE;
- /*
* The irq is shared with the iommu. If the runtime-pm state of the* vop-device is disabled the irq has to be targetted at the iommu.*/- if (!pm_runtime_get_if_in_use(vop->dev))
return IRQ_NONE;- if (WARN_ON(vop_core_clks_enable(vop)))
goto out;As I mentioned before, a WARN_ON() in an interrupt handler is a good way to make a bad problem even worse, and will give information (full register and stack dump) that is mostly useless to the context at hand. Turning it to a dev_warn_ratelimited() (or DRM_ERROR_RATELIMITED if you want to be DRM compliant) would be a better approach, IMHO.
Gah, sorry that I forgot to address your comment from v2 and thanks for the reminder.
- /*
- interrupt register has interrupt status, enable and clear bits, we
- must hold irq_lock to avoid a race with enable/disable_vblank().
@@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data) spin_unlock(&vop->irq_lock); /* This is expected for vop iommu irqs, since the irq is shared */
- if (!active_irqs)
return IRQ_NONE;
- if (!active_irqs) {
ret = IRQ_NONE;vop_core_clks_disable(vop);goto out;- }
A couple of nits: ret is already set to IRQ_NONE at this stage, and you could simply rewrite it as:
if (!active_irq) goto out_disable;
That's only one nit :-P ... but will change the patch accordingly.
Heiko
Hi Heiko,
On 06/12/2018 08:15 PM, Heiko Stuebner wrote:
From: Sandy Huang hjc@rock-chips.com
The vop irq is shared between vop and iommu and irq probing in the iommu driver moved to the probe function recently. This can in some cases lead to a stall if the irq is triggered while the vop driver still has it disabled, but the vop irq handler gets called.
hmmm, i think this patch actually fixes another stall case by removing the unpaired disable_irq() in vop_bind().
if we do disable_irq() in vop_bind() without enable it again in vop_unbind(), the irq_shutdown() called after vop_unbind()(when releasing devres) will confuse the irq depth, so the irq will stay disabled and could never be enabled again.
But there is no real need to disable the irq, as the vop can simply also track its enabled state and ignore irqs in that case. For this we can simply check the power-domain state of the vop, similar to how the iommu driver does it.
So remove the enable/disable handling and add appropriate condition to the irq handler.
changes in v2:
- move to just check the power-domain state
- add clock handling
changes in v3:
- clarify comment to speak of runtime-pm not power-domain
Fixes: d0b912bd4c23 ("iommu/rockchip: Request irqs in rk_iommu_probe()") Cc: stable@vger.kernel.org Signed-off-by: Sandy Huang hjc@rock-chips.com Signed-off-by: Heiko Stuebner heiko@sntech.de Tested-by: Ezequiel Garcia ezequiel@collabora.com
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 28 ++++++++++++++------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index 9a1f272e41c7..ae8a69793aed 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -573,8 +573,6 @@ static int vop_enable(struct drm_crtc *crtc)
spin_unlock(&vop->reg_lock);
enable_irq(vop->irq);
drm_crtc_vblank_on(crtc);
return 0;
@@ -618,8 +616,6 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
vop_dsp_hold_valid_irq_disable(vop);
disable_irq(vop->irq);
vop->is_enabled = false;
/*
@@ -1195,6 +1191,16 @@ static irqreturn_t vop_isr(int irq, void *data) uint32_t active_irqs; int ret = IRQ_NONE;
- /*
* The irq is shared with the iommu. If the runtime-pm state of the* vop-device is disabled the irq has to be targetted at the iommu.*/- if (!pm_runtime_get_if_in_use(vop->dev))
return IRQ_NONE;- if (WARN_ON(vop_core_clks_enable(vop)))
goto out;- /*
- interrupt register has interrupt status, enable and clear bits, we
- must hold irq_lock to avoid a race with enable/disable_vblank().
@@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data) spin_unlock(&vop->irq_lock);
/* This is expected for vop iommu irqs, since the irq is shared */
- if (!active_irqs)
return IRQ_NONE;
if (!active_irqs) {
ret = IRQ_NONE;vop_core_clks_disable(vop);goto out;}
if (active_irqs & DSP_HOLD_VALID_INTR) { complete(&vop->dsp_hold_completion);
@@ -1236,6 +1245,10 @@ static irqreturn_t vop_isr(int irq, void *data) DRM_DEV_ERROR(vop->dev, "Unknown VOP IRQs: %#02x\n", active_irqs);
- vop_core_clks_disable(vop);
+out:
- pm_runtime_put(vop->dev); return ret; }
@@ -1614,9 +1627,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data) 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:
Hi Heiko,
On Tue, Jun 12, 2018 at 9:15 PM Heiko Stuebner heiko@sntech.de wrote:
From: Sandy Huang hjc@rock-chips.com
The vop irq is shared between vop and iommu and irq probing in the iommu driver moved to the probe function recently. This can in some cases lead to a stall if the irq is triggered while the vop driver still has it disabled, but the vop irq handler gets called.
But there is no real need to disable the irq, as the vop can simply also track its enabled state and ignore irqs in that case. For this we can simply check the power-domain state of the vop, similar to how the iommu driver does it.
So remove the enable/disable handling and add appropriate condition to the irq handler.
changes in v2:
- move to just check the power-domain state
- add clock handling
changes in v3:
- clarify comment to speak of runtime-pm not power-domain
[snip]
@@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data) spin_unlock(&vop->irq_lock);
/* This is expected for vop iommu irqs, since the irq is shared */
if (!active_irqs)return IRQ_NONE;
if (!active_irqs) {ret = IRQ_NONE;vop_core_clks_disable(vop);
nit: If we're adding "out:", couldn't we also add "out_clks:" and move the call to vop_core_clks_disable() there?
goto out;} if (active_irqs & DSP_HOLD_VALID_INTR) { complete(&vop->dsp_hold_completion);@@ -1236,6 +1245,10 @@ static irqreturn_t vop_isr(int irq, void *data) DRM_DEV_ERROR(vop->dev, "Unknown VOP IRQs: %#02x\n", active_irqs);
vop_core_clks_disable(vop);+out:
pm_runtime_put(vop->dev); return ret;}
Other than that:
Reviewed-by: Tomasz Figa tfiga@chromium.org
Best regards, Tomasz
Am Montag, 18. Juni 2018, 10:44:58 CEST schrieb Tomasz Figa:
Hi Heiko,
On Tue, Jun 12, 2018 at 9:15 PM Heiko Stuebner heiko@sntech.de wrote:
From: Sandy Huang hjc@rock-chips.com
The vop irq is shared between vop and iommu and irq probing in the iommu driver moved to the probe function recently. This can in some cases lead to a stall if the irq is triggered while the vop driver still has it disabled, but the vop irq handler gets called.
But there is no real need to disable the irq, as the vop can simply also track its enabled state and ignore irqs in that case. For this we can simply check the power-domain state of the vop, similar to how the iommu driver does it.
So remove the enable/disable handling and add appropriate condition to the irq handler.
changes in v2:
- move to just check the power-domain state
- add clock handling
changes in v3:
- clarify comment to speak of runtime-pm not power-domain
[snip]
@@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data) spin_unlock(&vop->irq_lock);
/* This is expected for vop iommu irqs, since the irq is shared */
if (!active_irqs)return IRQ_NONE;
if (!active_irqs) {ret = IRQ_NONE;vop_core_clks_disable(vop);nit: If we're adding "out:", couldn't we also add "out_clks:" and move the call to vop_core_clks_disable() there?
goto out;} if (active_irqs & DSP_HOLD_VALID_INTR) { complete(&vop->dsp_hold_completion);@@ -1236,6 +1245,10 @@ static irqreturn_t vop_isr(int irq, void *data) DRM_DEV_ERROR(vop->dev, "Unknown VOP IRQs: %#02x\n", active_irqs);
vop_core_clks_disable(vop);+out:
pm_runtime_put(vop->dev); return ret;}
Other than that:
Reviewed-by: Tomasz Figa tfiga@chromium.org
That's similar to what Marc suggested and thus already part of v4 posted last tuesday, so I'll just carry over your Reviewed-by.
Could you possibly also give patch1 a nod of approval? So I can honor the strong suggestion in the drm-misc documentation? ;-)
Thanks Heiko
linux-stable-mirror@lists.linaro.org
-
Heiko Stuebner -
JeffyChen -
Marc Zyngier -
Tomasz Figa