6.11-stable review patch. If anyone has any objections, please let me know.
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From: Derek Foreman derek.foreman@collabora.com
[ Upstream commit f0fa69b5011a45394554fb8061d74fee4d7cd72c ]
The largest infoframe we create is the DRM (Dynamic Range Mastering) infoframe which is 26 bytes + a 4 byte header, for a total of 30 bytes.
With HDMI_MAX_INFOFRAME_SIZE set to 29 bytes, as it is now, we allocate too little space to pack a DRM infoframe in write_device_infoframe(), leading to an ENOSPC return from hdmi_infoframe_pack(), and never calling the connector's write_infoframe() vfunc.
Instead of having HDMI_MAX_INFOFRAME_SIZE defined in two places, replace HDMI_MAX_INFOFRAME_SIZE with HDMI_INFOFRAME_SIZE(MAX) and make MAX 27 bytes - which is defined by the HDMI specification to be the largest infoframe payload.
Fixes: f378b77227bc ("drm/connector: hdmi: Add Infoframes generation") Fixes: c602e4959a0c ("drm/connector: hdmi: Create Infoframe DebugFS entries")
Signed-off-by: Derek Foreman derek.foreman@collabora.com Acked-by: Maxime Ripard mripard@kernel.org Reviewed-by: Jani Nikula jani.nikula@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20240827163918.48160-1-derek.f... Signed-off-by: Maxime Ripard mripard@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/display/drm_hdmi_state_helper.c | 4 +--- drivers/gpu/drm/drm_debugfs.c | 4 +--- include/linux/hdmi.h | 9 +++++++++ 3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c index 7854820089ec6..feb7a3a759811 100644 --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c @@ -521,8 +521,6 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector, } EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_check);
-#define HDMI_MAX_INFOFRAME_SIZE 29 - static int clear_device_infoframe(struct drm_connector *connector, enum hdmi_infoframe_type type) { @@ -563,7 +561,7 @@ static int write_device_infoframe(struct drm_connector *connector, { const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs; struct drm_device *dev = connector->dev; - u8 buffer[HDMI_MAX_INFOFRAME_SIZE]; + u8 buffer[HDMI_INFOFRAME_SIZE(MAX)]; int ret; int len;
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c index 6b239a24f1dff..9d3e6dd68810e 100644 --- a/drivers/gpu/drm/drm_debugfs.c +++ b/drivers/gpu/drm/drm_debugfs.c @@ -520,8 +520,6 @@ static const struct file_operations drm_connector_fops = { .write = connector_write };
-#define HDMI_MAX_INFOFRAME_SIZE 29 - static ssize_t audio_infoframe_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { @@ -579,7 +577,7 @@ static ssize_t _f##_read_infoframe(struct file *filp, \ struct drm_connector *connector; \ union hdmi_infoframe *frame; \ struct drm_device *dev; \ - u8 buf[HDMI_MAX_INFOFRAME_SIZE]; \ + u8 buf[HDMI_INFOFRAME_SIZE(MAX)]; \ ssize_t len = 0; \ \ connector = filp->private_data; \ diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h index 3bb87bf6bc658..455f855bc0848 100644 --- a/include/linux/hdmi.h +++ b/include/linux/hdmi.h @@ -59,6 +59,15 @@ enum hdmi_infoframe_type { #define HDMI_DRM_INFOFRAME_SIZE 26 #define HDMI_VENDOR_INFOFRAME_SIZE 4
+/* + * HDMI 1.3a table 5-14 states that the largest InfoFrame_length is 27, + * not including the packet header or checksum byte. We include the + * checksum byte in HDMI_INFOFRAME_HEADER_SIZE, so this should allow + * HDMI_INFOFRAME_SIZE(MAX) to be the largest buffer we could ever need + * for any HDMI infoframe. + */ +#define HDMI_MAX_INFOFRAME_SIZE 27 + #define HDMI_INFOFRAME_SIZE(type) \ (HDMI_INFOFRAME_HEADER_SIZE + HDMI_ ## type ## _INFOFRAME_SIZE)