drm/bridge/sii8620: fix EDID fetch code

The patch adds handling errors during EDID fetch. Additionally it makes
code cleanup.

Change-Id: Icb94df6386d4b18ee5f7756991d0419b90763157
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>

diff --git a/drivers/gpu/drm/bridge/sii8620.c b/drivers/gpu/drm/bridge/sii8620.c
index 6a3d228..0390379 100644 (file)
--- a/drivers/gpu/drm/bridge/sii8620.c
+++ b/drivers/gpu/drm/bridge/sii8620.c
@@ -454,14 +454,10 @@ static void sii8620_mt_read_devcap(struct sii8620 *ctx, bool xdevcap)
 
 static void sii8620_fetch_edid(struct sii8620 *ctx)
 {
-       u8 lm_ddc;
-       u8 ddc_cmd;
-       u8 int3;
-       u8 cbus;
-       int i;
-       u8 *edid;
+       u8 lm_ddc, ddc_cmd, int3, cbus;
+       int fetched, i;
        int edid_len = EDID_LENGTH;
-       int fetched;
+       u8 *edid;
 
        sii8620_readb(ctx, REG_CBUS_STATUS);
        lm_ddc = sii8620_readb(ctx, REG_LM_DDC);
@@ -486,13 +482,13 @@ static void sii8620_fetch_edid(struct sii8620 *ctx)
 
        sii8620_write(ctx, REG_DDC_ADDR, 0x50 << 1);
 
-#define FETCH_SIZE 16
        edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
        if (!edid) {
                ctx->error = -ENOMEM;
                return;
        }
 
+#define FETCH_SIZE 16
        for (fetched = 0; fetched < edid_len; fetched += FETCH_SIZE) {
                sii8620_readb(ctx, REG_DDC_STATUS);
                sii8620_write_seq(ctx,
@@ -517,7 +513,8 @@ static void sii8620_fetch_edid(struct sii8620 *ctx)
 
                        if (!(cbus & BIT_CBUS_STATUS_CBUS_CONNECTED)) {
                                kfree(edid);
-                               return;
+                               edid = NULL;
+                               goto end;
                        }
                } while (1);
 
@@ -530,21 +527,27 @@ static void sii8620_fetch_edid(struct sii8620 *ctx)
                        u8 ext = ((struct edid *)edid)->extensions;
 
                        if (ext) {
+                               u8 *new_edid;
+
                                edid_len += ext * EDID_LENGTH;
-                               edid = krealloc(edid, edid_len, GFP_KERNEL);
+                               new_edid = krealloc(edid, edid_len, GFP_KERNEL);
+                               if (!new_edid) {
+                                       kfree(edid);
+                                       ctx->error = -ENOMEM;
+                                       return;
+                               }
+                               edid = new_edid;
                        }
                }
 
                if (fetched + FETCH_SIZE == edid_len)
-
-               sii8620_write(ctx, REG_INTR3, int3);
+                       sii8620_write(ctx, REG_INTR3, int3);
        }
 
        sii8620_write(ctx, REG_LM_DDC, lm_ddc);
 
-       if (ctx->edid)
-               kfree(ctx->edid);
-
+end:
+       kfree(ctx->edid);
        ctx->edid = (struct edid *)edid;
 }