On Mon, Jun 11, 2018 at 11:02:57PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> Adjust the EIR clearing to cope with the edge triggered IIR
> on i965/g4x. To guarantee an edge in the ISR master error bit
> we temporarily mask everything in EMR. As some of the EIR bits
> can't even be directly cleared we also borrow a trick from
> i915_clear_error_registers() and permanently mask any bit that
> remains high. No real thought given to how we might unmask them
> again once the cause for the error has been clered. I suppose
> on pre-g4x GPU reset will reinitialize EMR from scratch.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_irq.c | 105 ++++++++++++++++++++++++++++++++++++----
> drivers/gpu/drm/i915/i915_reg.h | 1 -
> 2 files changed, 96 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 59250ecbd0d9..985a137901fb 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3087,7 +3087,7 @@ static void i915_clear_error_registers(struct drm_i915_private *dev_priv)
> */
> DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masking\n", eir);
> I915_WRITE(EMR, I915_READ(EMR) | eir);
> - I915_WRITE(IIR, I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
> + I915_WRITE(IIR, I915_MASTER_ERROR_INTERRUPT);
> }
> }
>
> @@ -4107,6 +4107,81 @@ static int i8xx_irq_postinstall(struct drm_device *dev)
> return 0;
> }
>
> +static void i8xx_error_irq_ack(struct drm_i915_private *dev_priv,
> + u16 *eir, u16 *eir_stuck)
> +{
> + u16 emr;
> +
> + *eir = I915_READ16(EIR);
> +
> + if (*eir)
> + I915_WRITE16(EIR, *eir);
> +
> + *eir_stuck = I915_READ16(EIR);
Nit: this could store a new error interrupt after the above read to
eir_stuck instead of eir, but we won't lose the event in any case, so:
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
> + if (*eir_stuck == 0)
> + return;
> +
> + /*
> + * Toggle all EMR bits to make sure we get an edge
> + * in the ISR master error bit if we don't clear
> + * all the EIR bits. Otherwise the edge triggered
> + * IIR on i965/g4x wouldn't notice that an interrupt
> + * is still pending. Also some EIR bits can't be
> + * cleared except by handling the underlying error
> + * (or by a GPU reset) so we mask any bit that
> + * remains set.
> + */
> + emr = I915_READ16(EMR);
> + I915_WRITE16(EMR, 0xffff);
> + I915_WRITE16(EMR, emr | *eir_stuck);
> +}
> +
> +static void i8xx_error_irq_handler(struct drm_i915_private *dev_priv,
> + u16 eir, u16 eir_stuck)
> +{
> + DRM_DEBUG("Master Error: EIR 0x%04x\n", eir);
> +
> + if (eir_stuck)
> + DRM_DEBUG_DRIVER("EIR stuck: 0x%04x, masked\n", eir_stuck);
> +}
> +
> +static void i9xx_error_irq_ack(struct drm_i915_private *dev_priv,
> + u32 *eir, u32 *eir_stuck)
> +{
> + u32 emr;
> +
> + *eir = I915_READ(EIR);
> +
> + I915_WRITE(EIR, *eir);
> +
> + *eir_stuck = I915_READ(EIR);
> + if (*eir_stuck == 0)
> + return;
> +
> + /*
> + * Toggle all EMR bits to make sure we get an edge
> + * in the ISR master error bit if we don't clear
> + * all the EIR bits. Otherwise the edge triggered
> + * IIR on i965/g4x wouldn't notice that an interrupt
> + * is still pending. Also some EIR bits can't be
> + * cleared except by handling the underlying error
> + * (or by a GPU reset) so we mask any bit that
> + * remains set.
> + */
> + emr = I915_READ(EMR);
> + I915_WRITE(EMR, 0xffffffff);
> + I915_WRITE(EMR, emr | *eir_stuck);
> +}
> +
> +static void i9xx_error_irq_handler(struct drm_i915_private *dev_priv,
> + u32 eir, u32 eir_stuck)
> +{
> + DRM_DEBUG("Master Error, EIR 0x%08x\n", eir);
> +
> + if (eir_stuck)
> + DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masked\n", eir_stuck);
> +}
> +
> static irqreturn_t i8xx_irq_handler(int irq, void *arg)
> {
> struct drm_device *dev = arg;
> @@ -4121,6 +4196,7 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
>
> do {
> u32 pipe_stats[I915_MAX_PIPES] = {};
> + u16 eir = 0, eir_stuck = 0;
> u16 iir;
>
> iir = I915_READ16(IIR);
> @@ -4133,13 +4209,16 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
> * signalled in iir */
> i9xx_pipestat_irq_ack(dev_priv, iir, pipe_stats);
>
> + if (iir & I915_MASTER_ERROR_INTERRUPT)
> + i8xx_error_irq_ack(dev_priv, &eir, &eir_stuck);
> +
> I915_WRITE16(IIR, iir);
>
> if (iir & I915_USER_INTERRUPT)
> notify_ring(dev_priv->engine[RCS]);
>
> - if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
> - DRM_DEBUG("Command parser error, iir 0x%08x\n", iir);
> + if (iir & I915_MASTER_ERROR_INTERRUPT)
> + i8xx_error_irq_handler(dev_priv, eir, eir_stuck);
>
> i8xx_pipestat_irq_handler(dev_priv, iir, pipe_stats);
> } while (0);
> @@ -4220,6 +4299,7 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
>
> do {
> u32 pipe_stats[I915_MAX_PIPES] = {};
> + u32 eir = 0, eir_stuck = 0;
> u32 hotplug_status = 0;
> u32 iir;
>
> @@ -4237,13 +4317,16 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
> * signalled in iir */
> i9xx_pipestat_irq_ack(dev_priv, iir, pipe_stats);
>
> + if (iir & I915_MASTER_ERROR_INTERRUPT)
> + i9xx_error_irq_ack(dev_priv, &eir, &eir_stuck);
> +
> I915_WRITE(IIR, iir);
>
> if (iir & I915_USER_INTERRUPT)
> notify_ring(dev_priv->engine[RCS]);
>
> - if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
> - DRM_DEBUG("Command parser error, iir 0x%08x\n", iir);
> + if (iir & I915_MASTER_ERROR_INTERRUPT)
> + i9xx_error_irq_handler(dev_priv, eir, eir_stuck);
>
> if (hotplug_status)
> i9xx_hpd_irq_handler(dev_priv, hotplug_status);
> @@ -4297,14 +4380,14 @@ static int i965_irq_postinstall(struct drm_device *dev)
> I915_DISPLAY_PORT_INTERRUPT |
> I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
> I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
> - I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
> + I915_MASTER_ERROR_INTERRUPT);
>
> enable_mask =
> I915_ASLE_INTERRUPT |
> I915_DISPLAY_PORT_INTERRUPT |
> I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
> I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
> - I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT |
> + I915_MASTER_ERROR_INTERRUPT |
> I915_USER_INTERRUPT;
>
> if (IS_G4X(dev_priv))
> @@ -4364,6 +4447,7 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
>
> do {
> u32 pipe_stats[I915_MAX_PIPES] = {};
> + u32 eir = 0, eir_stuck = 0;
> u32 hotplug_status = 0;
> u32 iir;
>
> @@ -4380,6 +4464,9 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
> * signalled in iir */
> i9xx_pipestat_irq_ack(dev_priv, iir, pipe_stats);
>
> + if (iir & I915_MASTER_ERROR_INTERRUPT)
> + i9xx_error_irq_ack(dev_priv, &eir, &eir_stuck);
> +
> I915_WRITE(IIR, iir);
>
> if (iir & I915_USER_INTERRUPT)
> @@ -4388,8 +4475,8 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
> if (iir & I915_BSD_USER_INTERRUPT)
> notify_ring(dev_priv->engine[VCS]);
>
> - if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
> - DRM_DEBUG("Command parser error, iir 0x%08x\n", iir);
> + if (iir & I915_MASTER_ERROR_INTERRUPT)
> + i9xx_error_irq_handler(dev_priv, eir, eir_stuck);
>
> if (hotplug_status)
> i9xx_hpd_irq_handler(dev_priv, hotplug_status);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 987def26ce82..50a47753014b 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2805,7 +2805,6 @@ enum i915_power_well_id {
> #define I915_DISPLAY_PORT_INTERRUPT (1<<17)
> #define I915_DISPLAY_PIPE_C_HBLANK_INTERRUPT (1<<16)
> #define I915_MASTER_ERROR_INTERRUPT (1<<15)
> -#define I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT (1<<15)
> #define I915_DISPLAY_PIPE_B_HBLANK_INTERRUPT (1<<14)
> #define I915_GMCH_THERMAL_SENSOR_EVENT_INTERRUPT (1<<14) /* p-state */
> #define I915_DISPLAY_PIPE_A_HBLANK_INTERRUPT (1<<13)
> --
> 2.16.4
>
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