On Thu, Feb 20, 2025 at 06:07:52PM +0800, Jun Nie wrote:
> This change originates from the Qualcomm Android Linux driver. It is
> essential to support a dual-DSI configuration with two panels in
> some circumstances per testing. As the name suggests, this modification
> may enhance the bandwidth robustness of a bus.
Please start by describing the problem and the result of the changes.
Otherwise it reads as it "may enhance or may worsen" the robustness.
>
> Co-developed-by: Jonathan Marek <jonathan@xxxxxxxx>
> Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
> Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/dsi/dsi_host.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 42e100a8adca09d7b55afce0e2553e76d898744f..f59c4cd6bc8cdb31c1302f8e3ff395486c0b4898 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -2238,13 +2238,23 @@ int msm_dsi_host_cmd_rx(struct mipi_dsi_host *host,
> return ret;
> }
>
> +#define DSI_VBIF_CTRL (0x01CC - 4)
> +#define DSI_VBIF_CTRL_PRIORITY 0x07
> +
> void msm_dsi_host_cmd_xfer_commit(struct mipi_dsi_host *host, u32 dma_base,
> u32 len)
> {
> struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> + const struct msm_dsi_cfg_handler *cfg_hnd = msm_host->cfg_hnd;
> + u32 reg;
>
> dsi_write(msm_host, REG_DSI_DMA_BASE, dma_base);
> dsi_write(msm_host, REG_DSI_DMA_LEN, len);
> + if (cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V2_8_0) {
> + reg = dsi_read(msm_host, DSI_VBIF_CTRL);
> + reg |= (DSI_VBIF_CTRL_PRIORITY & 0x7);
> + dsi_write(msm_host, DSI_VBIF_CTRL, reg);
> + }
> dsi_write(msm_host, REG_DSI_TRIG_DMA, 1);
>
> /* Make sure trigger happens */
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
