Re: [PATCH] drm/bridge/synopsys: dsi: allow sending longer LP commands

From: Neil Armstrong <narmstrong@baylibre.com>
To: Yannick Fertre <yannick.fertre@st.com>,
	Philippe Cornu <philippe.cornu@st.com>,
	Benjamin Gaignard <benjamin.gaignard@st.com>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	dri-devel@lists.freedesktop.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm/bridge/synopsys: dsi: allow sending longer LP commands
Date: Mon, 7 Sep 2020 10:02:43 +0200	[thread overview]
Message-ID: <10134f03-3bb9-072b-a70f-edc972f7bf57@baylibre.com> (raw)
In-Reply-To: <20200701143131.841-1-yannick.fertre@st.com>

On 01/07/2020 16:31, Yannick Fertre wrote:
> From: Antonio Borneo <antonio.borneo@st.com>
> 
> Current code does not properly computes the max length of LP
> commands that can be send during H or V sync, and rely on static
> values.
> Limiting the max LP length to 4 byte during the V-sync is overly
> conservative.
> 
> Relax the limit and allows longer LP commands (16 bytes) to be
> sent during V-sync.
> 
> Signed-off-by: Antonio Borneo <antonio.borneo@st.com>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d580b2aa4ce9..1a24ea648ef8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -360,6 +360,15 @@ static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
>  	bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
>  	u32 val = 0;
>  
> +	/*
> +	 * TODO dw drv improvements
> +	 * largest packet sizes during hfp or during vsa/vpb/vfp
> +	 * should be computed according to byte lane, lane number and only
> +	 * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
> +	 */
> +	dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(16)
> +		  | INVACT_LPCMD_TIME(4));
> +
>  	if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
>  		val |= ACK_RQST_EN;
>  	if (lpm)
> @@ -611,14 +620,6 @@ static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
>  	dsi_write(dsi, DSI_DPI_VCID, DPI_VCID(dsi->channel));
>  	dsi_write(dsi, DSI_DPI_COLOR_CODING, color);
>  	dsi_write(dsi, DSI_DPI_CFG_POL, val);
> -	/*
> -	 * TODO dw drv improvements
> -	 * largest packet sizes during hfp or during vsa/vpb/vfp
> -	 * should be computed according to byte lane, lane number and only
> -	 * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
> -	 */
> -	dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(4)
> -		  | INVACT_LPCMD_TIME(4));
>  }
>  
>  static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
> 


Tested on Amlogic AXG (v1.21a)

Acked-by: Neil Armstrong <narmstrong@baylibre.com>

Applying to drm-misc-next

Thanks !
Neil

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