[PATCH v9 04/18] drm: exynos: dsi: Fix MIPI_DSI*_NO_* mode flags

[Marek Szyprowski]

Hi Jagan,

On 09.12.2022 16:23, Jagan Teki wrote:
> HFP/HBP/HSA/EOT_PACKET modes in Exynos DSI host specifies
> 0 = Enable and 1 = Disable.
>
> The logic for checking these mode flags was correct before
> the MIPI_DSI*_NO_* mode flag conversion.
>
> Fix the MIPI_DSI*_NO_* mode flags handling.
>
> Fixes: <0f3b68b66a6d> ("drm/dsi: Add _NO_ to MIPI_DSI_* flags disabling
> features")
> Reviewed-by: Nicolas Boichat <drinkcat at chromium.org>
> Reported-by: Sébastien Szymanski <sebastien.szymanski at armadeus.com>
> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> ---
> Changes for v9:
> - none
>
>   drivers/gpu/drm/exynos/exynos_drm_dsi.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> index e5b1540c4ae4..50a2a9ca88a9 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> @@ -805,15 +805,15 @@ static int exynos_dsi_init_link(struct exynos_dsi *dsi)
>   			reg |= DSIM_AUTO_MODE;
>   		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_HSE)
>   			reg |= DSIM_HSE_MODE;
> -		if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HFP))
> +		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HFP)
>   			reg |= DSIM_HFP_MODE;
> -		if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HBP))
> +		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HBP)
>   			reg |= DSIM_HBP_MODE;
> -		if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HSA))
> +		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HSA)
>   			reg |= DSIM_HSA_MODE;
>   	}
>   
> -	if (!(dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET))
> +	if (dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
>   		reg |= DSIM_EOT_DISABLE;
>   
>   	switch (dsi->format) {


Huh, this changes the logic in the driver! I've spent another half of 
the night trying to figure out why v8 and v9 doesn't work on all my 
Exynos boards with DSI panels again...

Please drop this patch from this series. If you want to get the Exynos 
DSI -> Samsung DSIM conversion merged, please focus on the core patches 
and don't add more random 'fixes' to each new version.

This change has to be discussed separately. The values written by the 
Exynos DSI driver to the registers ARE CORRECT and DSI panels work fine 
with such configuration. So either everything is correct, or these flags 
are reversed both in the Exynos DSI driver AND at least tested DSI 
panels (s6e8aa0, s6e3ha2, s6e63j0x03). I would need to check this in 
panel datasheets if I manage to get them.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland