linux-kernel - Re: [PATCH v6 4/8] drm/bridge: mhdp8546: Set input_bus_flags from atomic

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Message-ID: <cc84cc53-53b6-1ab2-7053-36b3d3d3c423@linaro.org>
Date:   Mon, 22 May 2023 10:05:42 +0200
From:   neil.armstrong@...aro.org
To:     Aradhya Bhatia <a-bhatia1@...com>,
        Tomi Valkeinen <tomba@...nel.org>,
        Jyri Sarha <jyri.sarha@....fi>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Andrzej Hajda <andrzej.hajda@...el.com>,
        Robert Foss <rfoss@...nel.org>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Rahul T R <r-ravikumar@...com>,
        Swapnil Jakhade <sjakhade@...ence.com>,
        Boris Brezillon <boris.brezillon@...labora.com>,
        Francesco Dolcini <francesco@...cini.it>
Cc:     DRI Development List <dri-devel@...ts.freedesktop.org>,
        Linux Kernel List <linux-kernel@...r.kernel.org>,
        Nishanth Menon <nm@...com>,
        Vignesh Raghavendra <vigneshr@...com>,
        Devarsh Thakkar <devarsht@...com>,
        Jayesh Choudhary <j-choudhary@...com>
Subject: Re: [PATCH v6 4/8] drm/bridge: mhdp8546: Set input_bus_flags from
 atomic_check

On 17/05/2023 07:48, Aradhya Bhatia wrote:
> Hi Neil,
> 
> On 16-May-23 12:54, Neil Armstrong wrote:
>> On 09/05/2023 11:30, Aradhya Bhatia wrote:
>>> From: Nikhil Devshatwar <nikhil.nd@...com>
>>>
>>> input_bus_flags are specified in drm_bridge_timings (legacy) as well
>>> as drm_bridge_state->input_bus_cfg.flags
>>>
>>> The flags from the timings will be deprecated. Bridges are supposed
>>> to validate and set the bridge state flags from atomic_check.
>>>
>>> Signed-off-by: Nikhil Devshatwar <nikhil.nd@...com>
>>> [a-bhatia1: replace timings in cdns_mhdp_platform_info by
>>> input_bus_flags]
>>> Signed-off-by: Aradhya Bhatia <a-bhatia1@...com>
>>> ---
>>>
>>> Notes:
>>>
>>>       changes from v5:
>>>       * removed the wrongly addded return statement in tfp410 driver.
>>>       * replaced the timings field in cdns_mhdp_platform_info by
>>>         input_bus_flags field, in order to get rid of bridge->timings
>>>         altogether.
>>>
>>>    drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c  | 11 ++++++++---
>>>    drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h  |  2 +-
>>>    drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.c |  9 ++++-----
>>>    drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.h |  2 +-
>>>    4 files changed, 14 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> index 623e4235c94f..a677b1267525 100644
>>> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> @@ -2189,6 +2189,13 @@ static int cdns_mhdp_atomic_check(struct
>>> drm_bridge *bridge,
>>>            return -EINVAL;
>>>        }
>>>    +    /*
>>> +     * There might be flags negotiation supported in future.
>>> +     * Set the bus flags in atomic_check statically for now.
>>> +     */
>>> +    if (mhdp->info)
>>> +        bridge_state->input_bus_cfg.flags =
>>> *mhdp->info->input_bus_flags;
>>> +
>>>        mutex_unlock(&mhdp->link_mutex);
>>>        return 0;
>>>    }
>>> @@ -2554,8 +2561,6 @@ static int cdns_mhdp_probe(struct
>>> platform_device *pdev)
>>>        mhdp->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID |
>>>                   DRM_BRIDGE_OP_HPD;
>>>        mhdp->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
>>> -    if (mhdp->info)
>>> -        mhdp->bridge.timings = mhdp->info->timings;
>>
>> Won't this cause a breakage because at this point in time
>> bridge.timings->input_bus_flags
>> seems to be still used by tidss right ?
>>
> 
> tidss was using the bridge.timings->input_bus_flags before the 7th
> patch[1] in this series.
> 
> After the patch, it only relies on bridge_state and display_info for bus
> flags and formats.

OK thanks, then:

Reviewed-by: Neil Armstrong <neil.armstrong@...aro.org>

if you resend a new version, please add this info in the commit message.

Neil

> 
> 
> Regards
> Aradhya
> 
> [1]: https://lore.kernel.org/all/20230509093036.3303-8-a-bhatia1@ti.com/
> 
> 
>>
>>>          ret = phy_init(mhdp->phy);
>>>        if (ret) {
>>> @@ -2642,7 +2647,7 @@ static const struct of_device_id mhdp_ids[] = {
>>>    #ifdef CONFIG_DRM_CDNS_MHDP8546_J721E
>>>        { .compatible = "ti,j721e-mhdp8546",
>>>          .data = &(const struct cdns_mhdp_platform_info) {
>>> -          .timings = &mhdp_ti_j721e_bridge_timings,
>>> +          .input_bus_flags = &mhdp_ti_j721e_bridge_input_bus_flags,
>>>              .ops = &mhdp_ti_j721e_ops,
>>>          },
>>>        },
>>> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
>>> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
>>> index bedddd510d17..bad2fc0c7306 100644
>>> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
>>> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
>>> @@ -336,7 +336,7 @@ struct cdns_mhdp_bridge_state {
>>>    };
>>>      struct cdns_mhdp_platform_info {
>>> -    const struct drm_bridge_timings *timings;
>>> +    const u32 *input_bus_flags;
>>>        const struct mhdp_platform_ops *ops;
>>>    };
>>>    diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.c
>>> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.c
>>> index dfe1b59514f7..12d04be4e242 100644
>>> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.c
>>> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.c
>>> @@ -71,8 +71,7 @@ const struct mhdp_platform_ops mhdp_ti_j721e_ops = {
>>>        .disable = cdns_mhdp_j721e_disable,
>>>    };
>>>    -const struct drm_bridge_timings mhdp_ti_j721e_bridge_timings = {
>>> -    .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE |
>>> -               DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE |
>>> -               DRM_BUS_FLAG_DE_HIGH,
>>> -};
>>> +const u32
>>> +mhdp_ti_j721e_bridge_input_bus_flags =
>>> DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE |
>>> +                       DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE |
>>> +                       DRM_BUS_FLAG_DE_HIGH;
>>> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.h
>>> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.h
>>> index 97d20d115a24..5ddca07a4255 100644
>>> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.h
>>> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-j721e.h
>>> @@ -14,6 +14,6 @@
>>>    struct mhdp_platform_ops;
>>>      extern const struct mhdp_platform_ops mhdp_ti_j721e_ops;
>>> -extern const struct drm_bridge_timings mhdp_ti_j721e_bridge_timings;
>>> +extern const u32 mhdp_ti_j721e_bridge_input_bus_flags;
>>>      #endif /* !CDNS_MHDP8546_J721E_H */
>>