The DP is using the same audio infoframe payload as hdmi, per DP 1.3
spec, but it has a different header. Provide a new interface here,
it just packs the payload.
Signed-off-by: Chris Zhong <[email protected]>
---
Changes in v2: None
drivers/video/hdmi.c | 66 ++++++++++++++++++++++++++++++++++++++--------------
include/linux/hdmi.h | 3 ++-
2 files changed, 50 insertions(+), 19 deletions(-)
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 1cf907e..e0b041e 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -240,6 +240,49 @@ int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
EXPORT_SYMBOL(hdmi_audio_infoframe_init);
/**
+ * hdmi_audio_infoframe_pack_payload() - write HDMI audio infoframe payload to
+ * binary buffer
+ * @frame: HDMI audio infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Packs the information contained in the @frame structure into a binary
+ * representation that can be written into the corresponding controller
+ * registers.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
+ void *buffer, size_t size)
+{
+ unsigned char channels;
+ u8 *ptr = buffer;
+
+ if (size < frame->length)
+ return -ENOSPC;
+
+ memset(buffer, 0, size);
+
+ if (frame->channels >= 2)
+ channels = frame->channels - 1;
+ else
+ channels = 0;
+
+ ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
+ ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
+ (frame->sample_size & 0x3);
+ ptr[2] = frame->coding_type_ext & 0x1f;
+ ptr[3] = frame->channel_allocation;
+ ptr[4] = (frame->level_shift_value & 0xf) << 3;
+
+ if (frame->downmix_inhibit)
+ ptr[4] |= BIT(7);
+
+ return 0;
+}
+EXPORT_SYMBOL(hdmi_audio_infoframe_pack_payload);
+
+/**
* hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
* @frame: HDMI audio infoframe
* @buffer: destination buffer
@@ -256,22 +299,15 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_init);
ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
void *buffer, size_t size)
{
- unsigned char channels;
u8 *ptr = buffer;
size_t length;
+ int ret;
length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
if (size < length)
return -ENOSPC;
- memset(buffer, 0, size);
-
- if (frame->channels >= 2)
- channels = frame->channels - 1;
- else
- channels = 0;
-
ptr[0] = frame->type;
ptr[1] = frame->version;
ptr[2] = frame->length;
@@ -279,16 +315,10 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
/* start infoframe payload */
ptr += HDMI_INFOFRAME_HEADER_SIZE;
-
- ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
- ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
- (frame->sample_size & 0x3);
- ptr[2] = frame->coding_type_ext & 0x1f;
- ptr[3] = frame->channel_allocation;
- ptr[4] = (frame->level_shift_value & 0xf) << 3;
-
- if (frame->downmix_inhibit)
- ptr[4] |= BIT(7);
+ ret = hdmi_audio_infoframe_pack_payload(frame, ptr,
+ size - HDMI_INFOFRAME_HEADER_SIZE);
+ if (ret)
+ return ret;
hdmi_infoframe_set_checksum(buffer, length);
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index d271ff2..d93c709 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -272,7 +272,8 @@ struct hdmi_audio_infoframe {
int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
void *buffer, size_t size);
-
+ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
+ void *buffer, size_t size);
enum hdmi_3d_structure {
HDMI_3D_STRUCTURE_INVALID = -1,
HDMI_3D_STRUCTURE_FRAME_PACKING = 0,
--
2.7.4
Some DP/HDMI sink need to receive the audio infoframe to play sound,
especially some multi-channel AV receiver, they need the
channel_allocation from infoframe to config the speakers. Send the
audio infoframe via SDP will make them work properly.
Signed-off-by: Chris Zhong <[email protected]>
---
Changes in v2:
- According to the advice of Sean Paul and Doug
use hdmi_audio_infoframe_pack_payload to pack the buffer
define a SDP_HEADER_SIZE
drivers/gpu/drm/rockchip/cdn-dp-core.c | 20 ++++++++++++++++++++
drivers/gpu/drm/rockchip/cdn-dp-reg.c | 27 +++++++++++++++++++++++++++
drivers/gpu/drm/rockchip/cdn-dp-reg.h | 6 ++++++
include/drm/drm_dp_helper.h | 1 +
4 files changed, 54 insertions(+)
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index 9b0b058..6a4fc66 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -802,6 +802,7 @@ static int cdn_dp_audio_hw_params(struct device *dev, void *data,
.sample_rate = params->sample_rate,
.channels = params->channels,
};
+ u8 buffer[HDMI_AUDIO_INFOFRAME_SIZE + EDP_SDP_HEADER_SIZE] = { 0 };
int ret;
mutex_lock(&dp->lock);
@@ -823,6 +824,25 @@ static int cdn_dp_audio_hw_params(struct device *dev, void *data,
goto out;
}
+ /*
+ * Prepare the infoframe header to SDP header per DP 1.3 spec, Table
+ * 2-98.
+ */
+ buffer[0] = 0;
+ buffer[1] = HDMI_INFOFRAME_TYPE_AUDIO;
+ buffer[2] = 0x1b;
+ buffer[3] = 0x48;
+
+ ret = hdmi_audio_infoframe_pack_payload(¶ms->cea,
+ &buffer[EDP_SDP_HEADER_SIZE],
+ HDMI_AUDIO_INFOFRAME_SIZE);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "Failed to pack audio infoframe: %d\n", ret);
+ goto out;
+ }
+
+ cdn_dp_sdp_write(dp, 0, buffer, sizeof(buffer));
+
ret = cdn_dp_audio_config(dp, &audio);
if (!ret)
dp->audio_info = audio;
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
index b14d211..4a818e4 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
@@ -286,6 +286,33 @@ int cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr, u8 value)
return ret;
}
+void cdn_dp_sdp_write(struct cdn_dp_device *dp, int entry_id, u8 *buf,
+ u32 buf_len)
+{
+ int idx;
+ u32 *packet = (u32 *)buf;
+ u32 num_packets = buf_len / 4;
+ u8 type;
+
+ if (buf_len < EDP_SDP_HEADER_SIZE) {
+ DRM_DEV_ERROR(dp->dev, "sdp buffer length: %d\n", buf_len);
+ return;
+ }
+
+ type = buf[1];
+
+ for (idx = 0; idx < num_packets; idx++)
+ writel(cpu_to_le32(*packet++), dp->regs + SOURCE_PIF_DATA_WR);
+
+ writel(entry_id, dp->regs + SOURCE_PIF_WR_ADDR);
+
+ writel(F_HOST_WR, dp->regs + SOURCE_PIF_WR_REQ);
+
+ writel(PIF_PKT_TYPE_VALID | F_PACKET_TYPE(type) | entry_id,
+ dp->regs + SOURCE_PIF_PKT_ALLOC_REG);
+ writel(PIF_PKT_ALLOC_WR_EN, dp->regs + SOURCE_PIF_PKT_ALLOC_WR_EN);
+}
+
int cdn_dp_load_firmware(struct cdn_dp_device *dp, const u32 *i_mem,
u32 i_size, const u32 *d_mem, u32 d_size)
{
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.h b/drivers/gpu/drm/rockchip/cdn-dp-reg.h
index c4bbb4a83..6ec0e81 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-reg.h
+++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.h
@@ -424,6 +424,11 @@
/* Reference cycles when using lane clock as reference */
#define LANE_REF_CYC 0x8000
+#define F_HOST_WR BIT(0)
+#define PIF_PKT_ALLOC_WR_EN BIT(0)
+#define PIF_PKT_TYPE_VALID (3 << 16)
+#define F_PACKET_TYPE(x) (((x) & 0xff) << 8)
+
enum voltage_swing_level {
VOLTAGE_LEVEL_0,
VOLTAGE_LEVEL_1,
@@ -478,5 +483,6 @@ int cdn_dp_set_video_status(struct cdn_dp_device *dp, int active);
int cdn_dp_config_video(struct cdn_dp_device *dp);
int cdn_dp_audio_stop(struct cdn_dp_device *dp, struct audio_info *audio);
int cdn_dp_audio_mute(struct cdn_dp_device *dp, bool enable);
+void cdn_dp_sdp_write(struct cdn_dp_device *dp, int entry_id, u8 *buf, u32 len);
int cdn_dp_audio_config(struct cdn_dp_device *dp, struct audio_info *audio);
#endif /* _CDN_DP_REG_H */
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index b17476a..5d5dd07 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -878,6 +878,7 @@ struct edp_sdp_header {
u8 HB3; /* 7:5 reserved, 4:0 number of valid data bytes */
} __packed;
+#define EDP_SDP_HEADER_SIZE 4
#define EDP_SDP_HEADER_REVISION_MASK 0x1F
#define EDP_SDP_HEADER_VALID_PAYLOAD_BYTES 0x1F
--
2.7.4
Hi,
On Tue, Jul 18, 2017 at 4:20 AM, Chris Zhong <[email protected]> wrote:
> The DP is using the same audio infoframe payload as hdmi, per DP 1.3
> spec, but it has a different header. Provide a new interface here,
> it just packs the payload.
>
> Signed-off-by: Chris Zhong <[email protected]>
> ---
>
> Changes in v2: None
>
> drivers/video/hdmi.c | 66 ++++++++++++++++++++++++++++++++++++++--------------
> include/linux/hdmi.h | 3 ++-
> 2 files changed, 50 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index 1cf907e..e0b041e 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -240,6 +240,49 @@ int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
> EXPORT_SYMBOL(hdmi_audio_infoframe_init);
>
> /**
> + * hdmi_audio_infoframe_pack_payload() - write HDMI audio infoframe payload to
> + * binary buffer
> + * @frame: HDMI audio infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Packs the information contained in the @frame structure into a binary
> + * representation that can be written into the corresponding controller
> + * registers.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
> + void *buffer, size_t size)
> +{
> + unsigned char channels;
> + u8 *ptr = buffer;
> +
> + if (size < frame->length)
You also need to return -ENOSPC if (size < 5). That's because below
you always write 5 elements into this array. I'll leave it to someone
with actual DRM experience to say whether they want a #define of some
sort here. Probably they do since someone made a #define for
"HDMI_INFOFRAME_HEADER_SIZE".
Also: you don't use frame->length anywhere in this function and it
doesn't seem to be related with packing the payload. Seems like you
shouldn't check it here.
> + return -ENOSPC;
> +
> + memset(buffer, 0, size);
I don't think the memset belongs here. It seems like all this
function is doing is setting up ptr[0] through ptr[4] and the memset()
doesn't belong with that, does it?
> @@ -256,22 +299,15 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_init);
> ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> void *buffer, size_t size)
> {
> - unsigned char channels;
> u8 *ptr = buffer;
> size_t length;
> + int ret;
>
> length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
>
> if (size < length)
> return -ENOSPC;
>
> - memset(buffer, 0, size);
It seems like the memset() belongs here, logically. This function
deals with the whole buffer so it should be clearing it.
> -
> - if (frame->channels >= 2)
> - channels = frame->channels - 1;
> - else
> - channels = 0;
> -
> ptr[0] = frame->type;
> ptr[1] = frame->version;
> ptr[2] = frame->length;
> @@ -279,16 +315,10 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>
> /* start infoframe payload */
> ptr += HDMI_INFOFRAME_HEADER_SIZE;
> -
> - ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
> - ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
> - (frame->sample_size & 0x3);
> - ptr[2] = frame->coding_type_ext & 0x1f;
> - ptr[3] = frame->channel_allocation;
> - ptr[4] = (frame->level_shift_value & 0xf) << 3;
> -
> - if (frame->downmix_inhibit)
> - ptr[4] |= BIT(7);
> + ret = hdmi_audio_infoframe_pack_payload(frame, ptr,
> + size - HDMI_INFOFRAME_HEADER_SIZE);
> + if (ret)
> + return ret;
>
> hdmi_infoframe_set_checksum(buffer, length);
>
> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
> index d271ff2..d93c709 100644
> --- a/include/linux/hdmi.h
> +++ b/include/linux/hdmi.h
> @@ -272,7 +272,8 @@ struct hdmi_audio_infoframe {
> int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
> ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> void *buffer, size_t size);
> -
> +ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
> + void *buffer, size_t size);
nit: seems like you're changing whitespace here (there used to be a
blank line before the enum).
> enum hdmi_3d_structure {
> HDMI_3D_STRUCTURE_INVALID = -1,
> HDMI_3D_STRUCTURE_FRAME_PACKING = 0,
> --
> 2.7.4
>
Hi Doug
On Tuesday, July 18, 2017 11:16 PM, Doug Anderson wrote:
> Hi,
>
> On Tue, Jul 18, 2017 at 4:20 AM, Chris Zhong <[email protected]> wrote:
>> The DP is using the same audio infoframe payload as hdmi, per DP 1.3
>> spec, but it has a different header. Provide a new interface here,
>> it just packs the payload.
>>
>> Signed-off-by: Chris Zhong <[email protected]>
>> ---
>>
>> Changes in v2: None
>>
>> drivers/video/hdmi.c | 66 ++++++++++++++++++++++++++++++++++++++--------------
>> include/linux/hdmi.h | 3 ++-
>> 2 files changed, 50 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
>> index 1cf907e..e0b041e 100644
>> --- a/drivers/video/hdmi.c
>> +++ b/drivers/video/hdmi.c
>> @@ -240,6 +240,49 @@ int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
>> EXPORT_SYMBOL(hdmi_audio_infoframe_init);
>>
>> /**
>> + * hdmi_audio_infoframe_pack_payload() - write HDMI audio infoframe payload to
>> + * binary buffer
>> + * @frame: HDMI audio infoframe
>> + * @buffer: destination buffer
>> + * @size: size of buffer
>> + *
>> + * Packs the information contained in the @frame structure into a binary
>> + * representation that can be written into the corresponding controller
>> + * registers.
>> + *
>> + * Returns 0 on success or a negative error code on failure.
>> + */
>> +ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
>> + void *buffer, size_t size)
>> +{
>> + unsigned char channels;
>> + u8 *ptr = buffer;
>> +
>> + if (size < frame->length)
> You also need to return -ENOSPC if (size < 5). That's because below
> you always write 5 elements into this array. I'll leave it to someone
> with actual DRM experience to say whether they want a #define of some
> sort here. Probably they do since someone made a #define for
> "HDMI_INFOFRAME_HEADER_SIZE".
>
> Also: you don't use frame->length anywhere in this function and it
> doesn't seem to be related with packing the payload. Seems like you
> shouldn't check it here.
Actually, I think it should be "if (size < HDMI_AUDIO_INFOFRAME_SIZE)"
>
>
>> + return -ENOSPC;
>> +
>> + memset(buffer, 0, size);
> I don't think the memset belongs here. It seems like all this
> function is doing is setting up ptr[0] through ptr[4] and the memset()
> doesn't belong with that, does it?
>
I think the length of payload is 10 Bytes(DB1~DB10), per audio infoframe
Format,
but we only use the front 5 Bytes, the back 5 bytes must be 0. If we
take the 10
bytes as a whole, it make sense.
>> @@ -256,22 +299,15 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_init);
>> ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>> void *buffer, size_t size)
>> {
>> - unsigned char channels;
>> u8 *ptr = buffer;
>> size_t length;
>> + int ret;
>>
>> length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
>>
>> if (size < length)
>> return -ENOSPC;
>>
>> - memset(buffer, 0, size);
> It seems like the memset() belongs here, logically. This function
> deals with the whole buffer so it should be clearing it.
>
>> -
>> - if (frame->channels >= 2)
>> - channels = frame->channels - 1;
>> - else
>> - channels = 0;
>> -
>> ptr[0] = frame->type;
>> ptr[1] = frame->version;
>> ptr[2] = frame->length;
>> @@ -279,16 +315,10 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>>
>> /* start infoframe payload */
>> ptr += HDMI_INFOFRAME_HEADER_SIZE;
>> -
>> - ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
>> - ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
>> - (frame->sample_size & 0x3);
>> - ptr[2] = frame->coding_type_ext & 0x1f;
>> - ptr[3] = frame->channel_allocation;
>> - ptr[4] = (frame->level_shift_value & 0xf) << 3;
>> -
>> - if (frame->downmix_inhibit)
>> - ptr[4] |= BIT(7);
>> + ret = hdmi_audio_infoframe_pack_payload(frame, ptr,
>> + size - HDMI_INFOFRAME_HEADER_SIZE);
>> + if (ret)
>> + return ret;
>>
>> hdmi_infoframe_set_checksum(buffer, length);
>>
>> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
>> index d271ff2..d93c709 100644
>> --- a/include/linux/hdmi.h
>> +++ b/include/linux/hdmi.h
>> @@ -272,7 +272,8 @@ struct hdmi_audio_infoframe {
>> int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
>> ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>> void *buffer, size_t size);
>> -
>> +ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
>> + void *buffer, size_t size);
> nit: seems like you're changing whitespace here (there used to be a
> blank line before the enum).
>
>> enum hdmi_3d_structure {
>> HDMI_3D_STRUCTURE_INVALID = -1,
>> HDMI_3D_STRUCTURE_FRAME_PACKING = 0,
>> --
>> 2.7.4
>>
>
>
--
Chris Zhong
Hi
On Tue, Jul 18, 2017 at 5:49 PM, Chris Zhong <[email protected]> wrote:
> Hi Doug
>
>
>
> On Tuesday, July 18, 2017 11:16 PM, Doug Anderson wrote:
>>
>> Hi,
>>
>> On Tue, Jul 18, 2017 at 4:20 AM, Chris Zhong <[email protected]> wrote:
>>>
>>> The DP is using the same audio infoframe payload as hdmi, per DP 1.3
>>> spec, but it has a different header. Provide a new interface here,
>>> it just packs the payload.
>>>
>>> Signed-off-by: Chris Zhong <[email protected]>
>>> ---
>>>
>>> Changes in v2: None
>>>
>>> drivers/video/hdmi.c | 66
>>> ++++++++++++++++++++++++++++++++++++++--------------
>>> include/linux/hdmi.h | 3 ++-
>>> 2 files changed, 50 insertions(+), 19 deletions(-)
>>>
>>> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
>>> index 1cf907e..e0b041e 100644
>>> --- a/drivers/video/hdmi.c
>>> +++ b/drivers/video/hdmi.c
>>> @@ -240,6 +240,49 @@ int hdmi_audio_infoframe_init(struct
>>> hdmi_audio_infoframe *frame)
>>> EXPORT_SYMBOL(hdmi_audio_infoframe_init);
>>>
>>> /**
>>> + * hdmi_audio_infoframe_pack_payload() - write HDMI audio infoframe
>>> payload to
>>> + * binary buffer
>>> + * @frame: HDMI audio infoframe
>>> + * @buffer: destination buffer
>>> + * @size: size of buffer
>>> + *
>>> + * Packs the information contained in the @frame structure into a binary
>>> + * representation that can be written into the corresponding controller
>>> + * registers.
>>> + *
>>> + * Returns 0 on success or a negative error code on failure.
>>> + */
>>> +ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe
>>> *frame,
>>> + void *buffer, size_t size)
>>> +{
>>> + unsigned char channels;
>>> + u8 *ptr = buffer;
>>> +
>>> + if (size < frame->length)
>>
>> You also need to return -ENOSPC if (size < 5). That's because below
>> you always write 5 elements into this array. I'll leave it to someone
>> with actual DRM experience to say whether they want a #define of some
>> sort here. Probably they do since someone made a #define for
>> "HDMI_INFOFRAME_HEADER_SIZE".
>>
>> Also: you don't use frame->length anywhere in this function and it
>> doesn't seem to be related with packing the payload. Seems like you
>> shouldn't check it here.
>
> Actually, I think it should be "if (size < HDMI_AUDIO_INFOFRAME_SIZE)"
Ah, OK. My main point was that this function needed to make sense on
its own. ...and the function in your patch writes to [0] through [4]
without actually confirming that there are at least 5 elements. I'd
be OK with:
if ((size < frame->length || size < HDMI_AUDIO_INFOFRAME_SIZE)
>>> + return -ENOSPC;
>>> +
>>> + memset(buffer, 0, size);
>>
>> I don't think the memset belongs here. It seems like all this
>> function is doing is setting up ptr[0] through ptr[4] and the memset()
>> doesn't belong with that, does it?
>>
> I think the length of payload is 10 Bytes(DB1~DB10), per audio infoframe
> Format,
> but we only use the front 5 Bytes, the back 5 bytes must be 0. If we take
> the 10
> bytes as a whole, it make sense.
OK, memset() here makes sense with what you say about the frame
needing to be 10 bytes big.
-Doug