Re: [Intel-gfx] [PATCH 09/12] drm/edid: Update range descriptor struct for EDID 1.4

On Tue, 2012-04-17 at 17:25 +0200, Takashi Iwai wrote:

At Fri, 13 Apr 2012 16:33:37 -0400, Adam Jackson wrote:

...

• u8 flags;
• union {

• struct {
  

• 	u8 reserved;
  

• 	u8 hfreq_start_khz; /* need to multiply by 2 */
  

• 	u8 c; /* need to divide by 2 */
  

• 	__le16 m;
  

• 	u8 k;
  

• 	u8 j; /* need to divide by 2 */
  

• } gtf2;
  

• struct {
  

• 	u8 version;
  

• 	u8 data1; /* high 6 bits: extra clock resolution */
  

• 	u8 data2; /* plus low 2 of above: max hactive */
  

• 	u8 supported_aspects;
  

• 	u8 flags; /* preferred aspect and blanking support */
  

• 	u8 supported_scalings;
  

• 	u8 preferred_refresh;
  

• } cvt;
  

These new structs must be marked with __attribute__((packed)) although the struct detailed_data_monitor_range itself is already marked. At least, with gcc 4.6 and x86-64 here, they get unaligned.

Eek. Good catch, thanks.

- ajax