Re: [PATCH 2/2] drm/i915: disable fbc due to Wa_16023588340

[Matthew Auld <matthew.auld@intel.com>]

On 26/06/2024 16:53, Rodrigo Vivi wrote:
> On Wed, Jun 19, 2024 at 03:31:27PM +0100, Matthew Auld wrote:
>> On BMG-G21 we need to disable fbc due to complications around the WA.
>>
>> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
>> Cc: Jonathan Cavitt <jonathan.cavitt@intel.com>
>> Cc: Matt Roper <matthew.d.roper@intel.com>
>> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
>> Cc: Vinod Govindapillai <vinod.govindapillai@intel.com>
>> Cc: intel-gfx@lists.freedesktop.org
>> ---
>>   drivers/gpu/drm/i915/display/intel_display_wa.h |  8 ++++++++
>>   drivers/gpu/drm/i915/display/intel_fbc.c        |  6 ++++++
>>   drivers/gpu/drm/xe/Makefile                     |  4 +++-
>>   drivers/gpu/drm/xe/display/xe_display_wa.c      | 16 ++++++++++++++++
>>   4 files changed, 33 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/gpu/drm/xe/display/xe_display_wa.c
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.h b/drivers/gpu/drm/i915/display/intel_display_wa.h
>> index 63201d09852c..be644ab6ae00 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_wa.h
>> +++ b/drivers/gpu/drm/i915/display/intel_display_wa.h
>> @@ -6,8 +6,16 @@
>>   #ifndef __INTEL_DISPLAY_WA_H__
>>   #define __INTEL_DISPLAY_WA_H__
>>   
>> +#include <linux/types.h>
>> +
>>   struct drm_i915_private;
>>   
>>   void intel_display_wa_apply(struct drm_i915_private *i915);
>>   
>> +#ifdef I915
>> +static inline bool intel_display_needs_wa_16023588340(struct drm_i915_private *i915) { return false; }
>> +#else
>> +bool intel_display_needs_wa_16023588340(struct drm_i915_private *i915);
>> +#endif
> 
> please avoid the ifdef I915 in new patches as we are trying to get away from that
> in favor of a clean separation.

Can you please share an example for the best way to do that here, with 
clean separation?

I can add a new .c just for intel_display_needs_wa_16023588340 and move 
it there, which then avoids the ifdef I think, but that then adds an 
entirely new file just for this tiny stub. Unless I can dump it 
somewhere else?

> 
>> +
>>   #endif
>> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
>> index 67116c9f1464..8488f82143a4 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
>> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
>> @@ -56,6 +56,7 @@
>>   #include "intel_display_device.h"
>>   #include "intel_display_trace.h"
>>   #include "intel_display_types.h"
>> +#include "intel_display_wa.h"
>>   #include "intel_fbc.h"
>>   #include "intel_fbc_regs.h"
>>   #include "intel_frontbuffer.h"
>> @@ -1237,6 +1238,11 @@ static int intel_fbc_check_plane(struct intel_atomic_state *state,
>>   		return 0;
>>   	}
>>   
>> +	if (intel_display_needs_wa_16023588340(i915)) {
>> +		plane_state->no_fbc_reason = "Wa_16023588340";
>> +		return 0;
>> +	}
>> +
>>   	/* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
>>   	if (i915_vtd_active(i915) && (IS_SKYLAKE(i915) || IS_BROXTON(i915))) {
>>   		plane_state->no_fbc_reason = "VT-d enabled";
>> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
>> index 0e16e5029081..f7521fd5db4c 100644
>> --- a/drivers/gpu/drm/xe/Makefile
>> +++ b/drivers/gpu/drm/xe/Makefile
>> @@ -34,7 +34,8 @@ uses_generated_oob := \
>>   	$(obj)/xe_ring_ops.o \
>>   	$(obj)/xe_vm.o \
>>   	$(obj)/xe_wa.o \
>> -	$(obj)/xe_ttm_stolen_mgr.o
>> +	$(obj)/xe_ttm_stolen_mgr.o \
>> +	$(obj)/display/xe_display_wa.o \
>>   
>>   $(uses_generated_oob): $(generated_oob)
>>   
>> @@ -192,6 +193,7 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
>>   	display/xe_display.o \
>>   	display/xe_display_misc.o \
>>   	display/xe_display_rps.o \
>> +	display/xe_display_wa.o \
>>   	display/xe_dsb_buffer.o \
>>   	display/xe_fb_pin.o \
>>   	display/xe_hdcp_gsc.o \
>> diff --git a/drivers/gpu/drm/xe/display/xe_display_wa.c b/drivers/gpu/drm/xe/display/xe_display_wa.c
>> new file mode 100644
>> index 000000000000..68e3d1959ad6
>> --- /dev/null
>> +++ b/drivers/gpu/drm/xe/display/xe_display_wa.c
>> @@ -0,0 +1,16 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright © 2024 Intel Corporation
>> + */
>> +
>> +#include "intel_display_wa.h"
>> +
>> +#include "xe_device.h"
>> +#include "xe_wa.h"
>> +
>> +#include <generated/xe_wa_oob.h>
>> +
>> +bool intel_display_needs_wa_16023588340(struct drm_i915_private *i915)
>> +{
>> +	return XE_WA(xe_root_mmio_gt(i915), 16023588340);
>> +}
>> -- 
>> 2.45.1
>>