| Message ID | 20240617105311.1587489-7-a-bhatia1@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: cdns-dsi: Fix the color-shift issue | expand |
On Mon, Jun 17, 2024 at 04:23:07PM GMT, Aradhya Bhatia wrote: > Allow the DCS Write FIFO in the cdns-dsi controller to reset before any > DCS packet is transmitted to the DSI sink device. > > The DCS FIFO reset is optional. Not all panels require it. But at > least one of the DSI based panel that uses Ilitek ILI9881C (DSI to DPI > bridge) doesn't work with without this reset. Could you please be more specific, why doesn't it work. Are there any leftover bytes in the FIFO? Is there any additional delay? > > Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com> > --- > drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c > index 05d2f4cc50da..87fdd07ca0bc 100644 > --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c > +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c > @@ -1037,6 +1037,9 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host, > > cdns_dsi_init_link(dsi); > > + /* Reset the DCS Write FIFO */ > + writel(0x00, dsi->regs + DIRECT_CMD_FIFO_RST); > + > ret = mipi_dsi_create_packet(&packet, msg); > if (ret) > goto out; > -- > 2.34.1 >
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 05d2f4cc50da..87fdd07ca0bc 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -1037,6 +1037,9 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host, cdns_dsi_init_link(dsi); + /* Reset the DCS Write FIFO */ + writel(0x00, dsi->regs + DIRECT_CMD_FIFO_RST); + ret = mipi_dsi_create_packet(&packet, msg); if (ret) goto out;
Allow the DCS Write FIFO in the cdns-dsi controller to reset before any DCS packet is transmitted to the DSI sink device. The DCS FIFO reset is optional. Not all panels require it. But at least one of the DSI based panel that uses Ilitek ILI9881C (DSI to DPI bridge) doesn't work with without this reset. Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com> --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 3 +++ 1 file changed, 3 insertions(+)