[PATCH] drm/i915/bmg: Read display register timeout

[Kandpal, Suraj]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Mitul
> Golani
> Sent: Thursday, July 25, 2024 6:28 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: intel-xe at lists.freedesktop.org
> Subject: [PATCH] drm/i915/bmg: Read display register timeout
> 
> Log the address of the register that caused the timeout interrupt by reading
> RMTIMEOUTREG_CAPTURE
> 
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_irq.c | 7 ++++++-
>  drivers/gpu/drm/i915/i915_reg.h                  | 2 ++
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.c
> b/drivers/gpu/drm/i915/display/intel_display_irq.c
> index 5219ba295c74..8e22f7ac3db0 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_irq.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_irq.c
> @@ -905,6 +905,11 @@ gen8_de_misc_irq_handler(struct drm_i915_private
> *dev_priv, u32 iir)
> 
>  			intel_pmdemand_irq_handler(dev_priv);
>  			found = true;
> +		} else if (iir & GEN8_DE_RM_TIMEOUT) {
> +			u32 val = intel_uncore_read(&dev_priv->uncore,
> +						    RMTIMEOUTREG_CAPTURE);
> +			drm_warn(&dev_priv->drm, "Register Access Timeout =
> 0x%x\n", val);
> +			found = true;
>  		}
>  	} else if (iir & GEN8_DE_MISC_GSE) {
>  		intel_opregion_asle_intr(dev_priv);
> @@ -1710,7 +1715,7 @@ void gen8_de_irq_postinstall(struct
> drm_i915_private *dev_priv)
> 
>  	if (DISPLAY_VER(dev_priv) >= 14) {
>  		de_misc_masked |= XELPDP_PMDEMAND_RSPTOUT_ERR |
> -				  XELPDP_PMDEMAND_RSP;
> +				  XELPDP_PMDEMAND_RSP |
> GEN8_DE_RM_TIMEOUT;

Do you only want to log it for display_ver > = 14,  I would expect it to be logged
Even for gen 8 so maybe this isn't the right place to OR it.

>  	} else if (DISPLAY_VER(dev_priv) >= 11) {
>  		enum port port;
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h index 0e3d79227e3c..858ce8a5d929
> 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2396,6 +2396,7 @@
> 
>  /* Display Internal Timeout Register */
>  #define RM_TIMEOUT		_MMIO(0x42060)
> +#define RMTIMEOUTREG_CAPTURE	_MMIO(0x420E0)

Maybe RM_TIMEOUT_REG_CAPTURE seems cleaner.

Regards,
Suraj Kandpal
>  #define  MMIO_TIMEOUT_US(us)	((us) << 0)
> 
>  /* interrupts */
> @@ -2574,6 +2575,7 @@
>  #define GEN8_DE_MISC_IMR _MMIO(0x44464)  #define GEN8_DE_MISC_IIR
> _MMIO(0x44468)  #define GEN8_DE_MISC_IER _MMIO(0x4446c)
> +#define  GEN8_DE_RM_TIMEOUT		REG_BIT(29)
>  #define  XELPDP_PMDEMAND_RSPTOUT_ERR	REG_BIT(27)
>  #define  GEN8_DE_MISC_GSE		REG_BIT(27)
>  #define  GEN8_DE_EDP_PSR		REG_BIT(19)
> --
> 2.45.2