OMAPDSS: DSI: fix dsi_get_dsidev_from_id()

If dsi_get_dsidev_from_id() is called with a DSI module id that does not
exist on the board, the function will crash as omap_dss_get_output()
will return NULL.

This happens on omap3 boards when dumping DSI clocks, as the dumping
code will try to get the dsidev for DSI modules 0 and 1, but omap3 only
has DSI module 0.

Also clean up the id -> output mapping, so that if the function is
called with invalid module ID it will return NULL.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Archit Taneja <archit@ti.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index af07ec6a83bd..7d0db2bf2fc6 100644
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c
@@ -364,11 +364,20 @@ struct platform_device *dsi_get_dsidev_from_id(int module)
         struct omap_dss_output *out;
         enum omap_dss_output_id id;
 
-        id = module == 0 ? OMAP_DSS_OUTPUT_DSI1 : OMAP_DSS_OUTPUT_DSI2;
+        switch (module) {
+        case 0:
+                id = OMAP_DSS_OUTPUT_DSI1;
+                break;
+        case 1:
+                id = OMAP_DSS_OUTPUT_DSI2;
+                break;
+        default:
+                return NULL;
+        }
 
         out = omap_dss_get_output(id);
 
-        return out->pdev;
+        return out ? out->pdev : NULL;
 }
 
 static inline void dsi_write_reg(struct platform_device *dsidev,