Merge commit 'v2.6.39-rc3' into for-2.6.39

[pandora-kernel.git] / drivers / gpu / drm / drm_edid.c

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a245d17..adc9358 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -230,24 +230,32 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
                      int block, int len)
 {
        unsigned char start = block * EDID_LENGTH;
-       struct i2c_msg msgs[] = {
-               {
-                       .addr   = DDC_ADDR,
-                       .flags  = 0,
-                       .len    = 1,
-                       .buf    = &start,
-               }, {
-                       .addr   = DDC_ADDR,
-                       .flags  = I2C_M_RD,
-                       .len    = len,
-                       .buf    = buf,
-               }
-       };
+       int ret, retries = 5;
 
-       if (i2c_transfer(adapter, msgs, 2) == 2)
-               return 0;
+       /* The core i2c driver will automatically retry the transfer if the
+        * adapter reports EAGAIN. However, we find that bit-banging transfers
+        * are susceptible to errors under a heavily loaded machine and
+        * generate spurious NAKs and timeouts. Retrying the transfer
+        * of the individual block a few times seems to overcome this.
+        */
+       do {
+               struct i2c_msg msgs[] = {
+                       {
+                               .addr   = DDC_ADDR,
+                               .flags  = 0,
+                               .len    = 1,
+                               .buf    = &start,
+                       }, {
+                               .addr   = DDC_ADDR,
+                               .flags  = I2C_M_RD,
+                               .len    = len,
+                               .buf    = buf,
+                       }
+               };
+               ret = i2c_transfer(adapter, msgs, 2);
+       } while (ret != 2 && --retries);
 
-       return -1;
+       return ret == 2 ? 0 : -1;
 }
 
 static u8 *
@@ -449,12 +457,11 @@ static void edid_fixup_preferred(struct drm_connector *connector,
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
                                           int hsize, int vsize, int fresh)
 {
+       struct drm_display_mode *mode = NULL;
        int i;
-       struct drm_display_mode *ptr, *mode;
 
-       mode = NULL;
        for (i = 0; i < drm_num_dmt_modes; i++) {
-               ptr = &drm_dmt_modes[i];
+               const struct drm_display_mode *ptr = &drm_dmt_modes[i];
                if (hsize == ptr->hdisplay &&
                        vsize == ptr->vdisplay &&
                        fresh == drm_mode_vrefresh(ptr)) {
@@ -885,7 +892,7 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
 }
 
 static bool
-mode_is_rb(struct drm_display_mode *mode)
+mode_is_rb(const struct drm_display_mode *mode)
 {
        return (mode->htotal - mode->hdisplay == 160) &&
               (mode->hsync_end - mode->hdisplay == 80) &&
@@ -894,7 +901,8 @@ mode_is_rb(struct drm_display_mode *mode)
 }
 
 static bool
-mode_in_hsync_range(struct drm_display_mode *mode, struct edid *edid, u8 *t)
+mode_in_hsync_range(const struct drm_display_mode *mode,
+                   struct edid *edid, u8 *t)
 {
        int hsync, hmin, hmax;
 
@@ -910,7 +918,8 @@ mode_in_hsync_range(struct drm_display_mode *mode, struct edid *edid, u8 *t)
 }
 
 static bool
-mode_in_vsync_range(struct drm_display_mode *mode, struct edid *edid, u8 *t)
+mode_in_vsync_range(const struct drm_display_mode *mode,
+                   struct edid *edid, u8 *t)
 {
        int vsync, vmin, vmax;
 
@@ -941,7 +950,7 @@ range_pixel_clock(struct edid *edid, u8 *t)
 }
 
 static bool
-mode_in_range(struct drm_display_mode *mode, struct edid *edid,
+mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
              struct detailed_timing *timing)
 {
        u32 max_clock;
@@ -1288,7 +1297,7 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 /**
  * Search EDID for CEA extension block.
  */
-static u8 *drm_find_cea_extension(struct edid *edid)
+u8 *drm_find_cea_extension(struct edid *edid)
 {
        u8 *edid_ext = NULL;
        int i;
@@ -1309,6 +1318,7 @@ static u8 *drm_find_cea_extension(struct edid *edid)
 
        return edid_ext;
 }
+EXPORT_SYMBOL(drm_find_cea_extension);
 
 /**
  * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
@@ -1472,7 +1482,7 @@ int drm_add_modes_noedid(struct drm_connector *connector,
                        int hdisplay, int vdisplay)
 {
        int i, count, num_modes = 0;
-       struct drm_display_mode *mode, *ptr;
+       struct drm_display_mode *mode;
        struct drm_device *dev = connector->dev;
 
        count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
@@ -1482,7 +1492,7 @@ int drm_add_modes_noedid(struct drm_connector *connector,
                vdisplay = 0;
 
        for (i = 0; i < count; i++) {
-               ptr = &drm_dmt_modes[i];
+               const struct drm_display_mode *ptr = &drm_dmt_modes[i];
                if (hdisplay && vdisplay) {
                        /*
                         * Only when two are valid, they will be used to check