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path: root/sound/pci/hda/hda_eld.c
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Diffstat (limited to 'sound/pci/hda/hda_eld.c')
-rw-r--r--sound/pci/hda/hda_eld.c28
1 files changed, 19 insertions, 9 deletions
diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
index 7ae7578bdcc..c1da422e085 100644
--- a/sound/pci/hda/hda_eld.c
+++ b/sound/pci/hda/hda_eld.c
@@ -347,18 +347,28 @@ int snd_hdmi_get_eld(struct hdmi_eld *eld,
for (i = 0; i < size; i++) {
unsigned int val = hdmi_get_eld_data(codec, nid, i);
+ /*
+ * Graphics driver might be writing to ELD buffer right now.
+ * Just abort. The caller will repoll after a while.
+ */
if (!(val & AC_ELDD_ELD_VALID)) {
- if (!i) {
- snd_printd(KERN_INFO
- "HDMI: invalid ELD data\n");
- ret = -EINVAL;
- goto error;
- }
snd_printd(KERN_INFO
"HDMI: invalid ELD data byte %d\n", i);
- val = 0;
- } else
- val &= AC_ELDD_ELD_DATA;
+ ret = -EINVAL;
+ goto error;
+ }
+ val &= AC_ELDD_ELD_DATA;
+ /*
+ * The first byte cannot be zero. This can happen on some DVI
+ * connections. Some Intel chips may also need some 250ms delay
+ * to return non-zero ELD data, even when the graphics driver
+ * correctly writes ELD content before setting ELD_valid bit.
+ */
+ if (!val && !i) {
+ snd_printdd(KERN_INFO "HDMI: 0 ELD data\n");
+ ret = -EINVAL;
+ goto error;
+ }
buf[i] = val;
}