[Freedreno] [PATCH 3/3] drm/msm/dpu: Add interface support for CRC debugfs

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Thu Jun 2 22:51:13 UTC 2022


On 28/05/2022 01:23, Jessica Zhang wrote:
> 
> 
> On 5/27/2022 12:46 PM, Dmitry Baryshkov wrote:
>> On 27/05/2022 21:54, Jessica Zhang wrote:
>>> Add support for writing CRC values for the interface block to
>>> the debugfs by calling the necessary MISR setup/collect methods.
>>>
>>> Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
>>> ---
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    | 43 ++++++++++++++-
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  3 +
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 61 +++++++++++++++++++++
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 22 ++++++++
>>>   4 files changed, 128 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> index ae09466663cf..e830fb1e910d 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> @@ -79,6 +79,8 @@ static enum dpu_crtc_crc_source 
>>> dpu_crtc_parse_crc_source(const char *src_name)
>>>       if (!strcmp(src_name, "auto") ||
>>>           !strcmp(src_name, "lm"))
>>>           return DPU_CRTC_CRC_SOURCE_LAYER_MIXER;
>>> +    if (!strcmp(src_name, "intf"))
>>> +        return DPU_CRTC_CRC_SOURCE_INTF;
>>>       return DPU_CRTC_CRC_SOURCE_INVALID;
>>>   }
>>> @@ -94,8 +96,18 @@ static int dpu_crtc_verify_crc_source(struct 
>>> drm_crtc *crtc,
>>>           return -EINVAL;
>>>       }
>>> -    if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
>>> +    if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER) {
>>>           *values_cnt = crtc_state->num_mixers;
>>> +    } else if (source == DPU_CRTC_CRC_SOURCE_INTF) {
>>> +        struct drm_encoder *drm_enc = get_encoder_from_crtc(crtc);
>>
>> Let's do this correctly from the beginning. The CRTC can drive several 
>> encoders. Do we want to get CRC from all of them or just from the 
>> first one?
> 
> In the case of multiple encoders, it would be better to collect CRCs 
> from all of them.

Then this should become a loop.

> 
>>
>>> +
>>> +        if (!drm_enc) {
>>> +            DRM_ERROR("no encoder found for crtc %d\n", crtc->index);
>>> +            return -ENODATA;
>>> +        }
>>> +
>>> +        *values_cnt = dpu_encoder_get_num_phys(drm_enc);
>>> +    }
>>>       return 0;
>>>   }
>>> @@ -116,6 +128,18 @@ static void dpu_crtc_setup_lm_misr(struct 
>>> dpu_crtc_state *crtc_state)
>>>       }
>>>   }
>>> +static void dpu_crtc_setup_encoder_misr(struct drm_crtc *crtc)
>>> +{
>>> +    struct drm_encoder *drm_enc = get_encoder_from_crtc(crtc);
>>> +
>>> +    if (!drm_enc) {
>>> +        DRM_ERROR("no encoder found for crtc %d\n", crtc->index);
>>> +        return;
>>> +    }
>>> +
>>> +    dpu_encoder_setup_misr(drm_enc);
>>> +}
>>> +
>>>   static int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const 
>>> char *src_name)
>>>   {
>>>       enum dpu_crtc_crc_source source = 
>>> dpu_crtc_parse_crc_source(src_name);
>>> @@ -164,6 +188,8 @@ static int dpu_crtc_set_crc_source(struct 
>>> drm_crtc *crtc, const char *src_name)
>>>       if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
>>>           dpu_crtc_setup_lm_misr(crtc_state);
>>> +    else if (source == DPU_CRTC_CRC_SOURCE_INTF)
>>> +        dpu_crtc_setup_encoder_misr(crtc);
>>>   cleanup:
>>>       drm_modeset_unlock(&crtc->mutex);
>>> @@ -212,6 +238,18 @@ static int dpu_crtc_get_lm_crc(struct drm_crtc 
>>> *crtc, struct dpu_crtc_state *crt
>>>               drm_crtc_accurate_vblank_count(crtc), crcs);
>>>   }
>>> +static int dpu_crtc_get_encoder_crc(struct drm_crtc *crtc)
>>> +{
>>> +    struct drm_encoder *drm_enc =  get_encoder_from_crtc(crtc);
>>> +
>>> +    if (!drm_enc) {
>>> +        DRM_ERROR("no encoder found for crtc %d\n", crtc->index);
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    return dpu_encoder_get_crc(drm_enc);
>>> +}
>>> +
>>>   static int dpu_crtc_get_crc(struct drm_crtc *crtc)
>>>   {
>>>       struct dpu_crtc_state *crtc_state;
>>> @@ -227,6 +265,9 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc)
>>>       if (crtc_state->crc_source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
>>>           return dpu_crtc_get_lm_crc(crtc, crtc_state);
>>> +    if (crtc_state->crc_source == DPU_CRTC_CRC_SOURCE_INTF)
>>> +        return dpu_crtc_get_encoder_crc(crtc);
>>> +
>>>       return 0;
>>>   }
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> index b8785c394fcc..a60af034905d 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> @@ -1,5 +1,6 @@
>>>   /* SPDX-License-Identifier: GPL-2.0-only */
>>>   /*
>>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>>> reserved.
>>>    * Copyright (c) 2015-2021 The Linux Foundation. All rights reserved.
>>>    * Copyright (C) 2013 Red Hat
>>>    * Author: Rob Clark <robdclark at gmail.com>
>>> @@ -73,11 +74,13 @@ struct dpu_crtc_smmu_state_data {
>>>    * enum dpu_crtc_crc_source: CRC source
>>>    * @DPU_CRTC_CRC_SOURCE_NONE: no source set
>>>    * @DPU_CRTC_CRC_SOURCE_LAYER_MIXER: CRC in layer mixer
>>> + * @DPU_CRTC_CRC_SOURCE_INTF: CRC in phys interface
>>>    * @DPU_CRTC_CRC_SOURCE_INVALID: Invalid source
>>>    */
>>>   enum dpu_crtc_crc_source {
>>>       DPU_CRTC_CRC_SOURCE_NONE = 0,
>>>       DPU_CRTC_CRC_SOURCE_LAYER_MIXER,
>>> +    DPU_CRTC_CRC_SOURCE_INTF,
>>>       DPU_CRTC_CRC_SOURCE_MAX,
>>>       DPU_CRTC_CRC_SOURCE_INVALID = -1
>>>   };
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> index 52516eb20cb8..7740515f462d 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> @@ -14,6 +14,7 @@
>>>   #include <drm/drm_crtc.h>
>>>   #include <drm/drm_file.h>
>>> +#include <drm/drm_vblank.h>
>>>   #include <drm/drm_probe_helper.h>
>>>   #include "msm_drv.h"
>>> @@ -225,6 +226,66 @@ bool dpu_encoder_is_widebus_enabled(const struct 
>>> drm_encoder *drm_enc)
>>>       return dpu_enc->wide_bus_en;
>>>   }
>>> +int dpu_encoder_get_num_phys(const struct drm_encoder *drm_enc)
>>> +{
>>> +    struct dpu_encoder_virt *dpu_enc;
>>> +
>>> +    dpu_enc = to_dpu_encoder_virt(drm_enc);
>>> +
>>> +    return dpu_enc->num_phys_encs;
>>> +}
>>> +
>>> +void dpu_encoder_setup_misr(const struct drm_encoder *drm_enc)
>>> +{
>>> +    struct dpu_encoder_virt *dpu_enc;
>>> +
>>> +    int i;
>>> +
>>> +    dpu_enc = to_dpu_encoder_virt(drm_enc);
>>> +
>>> +    for (i = 0; i < dpu_enc->num_phys_encs; i++) {
>>> +        struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
>>> +
>>> +        if (!phys->hw_intf || !phys->hw_intf->ops.setup_misr)
>>> +            continue;
>>
>> Does WB support CRC?
> 
> AFAIK, no.
> 
>>
>>> +
>>> +        phys->hw_intf->ops.setup_misr(phys->hw_intf, true, 1);
>>> +    }
>>> +}
>>> +
>>> +int dpu_encoder_get_crc(const struct drm_encoder *drm_enc)
>>> +{
>>> +    struct dpu_encoder_virt *dpu_enc;
>>> +    u32 crcs[MAX_PHYS_ENCODERS_PER_VIRTUAL];
>>> +
>>> +    int i, rc;
>>> +
>>> +    if (!drm_enc->crtc) {
>>> +        DRM_ERROR("no crtc found for encoder %d\n", drm_enc->index);
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    dpu_enc = to_dpu_encoder_virt(drm_enc);
>>> +
>>> +    for (i = 0; i < dpu_enc->num_phys_encs; i++) {
>>> +        struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
>>> +
>>> +        if (!phys->hw_intf || !phys->hw_intf->ops.collect_misr)
>>> +            continue;
>>> +
>>> +        rc = phys->hw_intf->ops.collect_misr(phys->hw_intf, &crcs[i]);
>>
>> This doesn't look fully correct. Do we need to skip the indices for 
>> the phys without a backing hw_intf?
> 
> Sorry if I'm misunderstanding your question, but don't we need to have a 
> backing hw_intf (and skip if there isn't any) since the methods for 
> collecting/setting MISR registers is within the hw_intf?

Yes. So the question if we should skip the phys and leave the crcs[i] 
untouched, skip the phys and sset crcs[i] to 0 or change 
dpu_crtc_parse_crc_source() to return the number of intf-backed 
phys_enc's and do not skip any crcs[i].


> 
>>
>>> +
>>
>> Extra empty line.
> 
> Noted
> 
>>
>>> +        if (rc) {
>>> +            if (rc != -ENODATA)
>>
>> Do we need to handle ENODATA in any specific way (like zeroing the 
>> crcs[i])? If not, I'd suggest to drop this return code. Let's make an 
>> error always an error.
> 
> This is a carry-over from this change [1]. We wanted to have the ENODATA 
> check to avoid spamming the driver debug logs when CRC is disabled for 
> this block.
> 
> [1] 
> https://gitlab.freedesktop.org/drm/msm/-/commit/3ce8bdca394fc606b55e7c5ed779d171aaae5d09 

Thanks for the reminder. I commented this in the previous patch now.



-- 
With best wishes
Dmitry


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