Some manufacturers have intentionally put an EDID that differs from the EDID on the internal panel on laptops. Drivers that prefer to fetch this EDID can set a bit on the drm_connector to indicate that the DRM EDID helpers should try to fetch it and it is preferred if it's present. Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> --- drivers/gpu/drm/Kconfig | 1 + drivers/gpu/drm/drm_edid.c | 109 +++++++++++++++++++++++++++++++++--- include/drm/drm_connector.h | 6 ++ include/drm/drm_edid.h | 1 + 4 files changed, 109 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 872edb47bb53..3db89e6af01d 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -8,6 +8,7 @@ menuconfig DRM tristate "Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)" depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && HAS_DMA + depends on (ACPI_VIDEO || ACPI_VIDEO=n) select DRM_PANEL_ORIENTATION_QUIRKS select DRM_KMS_HELPER if DRM_FBDEV_EMULATION select FB_CORE if DRM_FBDEV_EMULATION diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 923c4423151c..cdc30c6d05d5 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -28,6 +28,7 @@ * DEALINGS IN THE SOFTWARE. */ +#include <acpi/video.h> #include <linux/bitfield.h> #include <linux/cec.h> #include <linux/hdmi.h> @@ -2188,6 +2189,58 @@ drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len) return ret == xfers ? 0 : -1; } +/** + * drm_do_probe_acpi_edid() - get EDID information via ACPI _DDC + * @data: struct drm_connector + * @buf: EDID data buffer to be filled + * @block: 128 byte EDID block to start fetching from + * @len: EDID data buffer length to fetch + * + * Try to fetch EDID information by calling acpi_video_get_edid() function. + * + * Return: 0 on success or error code on failure. + */ +static int +drm_do_probe_acpi_edid(void *data, u8 *buf, unsigned int block, size_t len) +{ + struct drm_connector *connector = data; + struct drm_device *ddev = connector->dev; + struct acpi_device *acpidev = ACPI_COMPANION(ddev->dev); + unsigned char start = block * EDID_LENGTH; + void *edid; + int r; + + if (!acpidev) + return -ENODEV; + + switch (connector->connector_type) { + case DRM_MODE_CONNECTOR_LVDS: + case DRM_MODE_CONNECTOR_eDP: + break; + default: + return -EINVAL; + } + + /* fetch the entire edid from BIOS */ + r = acpi_video_get_edid(acpidev, ACPI_VIDEO_DISPLAY_LCD, -1, &edid); + if (r < 0) { + DRM_DEBUG_KMS("Failed to get EDID from ACPI: %d\n", r); + return r; + } + if (len > r || start > r || start + len > r) { + r = -EINVAL; + goto cleanup; + } + + memcpy(buf, edid + start, len); + r = 0; + +cleanup: + kfree(edid); + + return r; +} + static void connector_bad_edid(struct drm_connector *connector, const struct edid *edid, int num_blocks) { @@ -2621,7 +2674,8 @@ EXPORT_SYMBOL(drm_probe_ddc); * @connector: connector we're probing * @adapter: I2C adapter to use for DDC * - * Poke the given I2C channel to grab EDID data if possible. If found, + * If the connector allows it, try to fetch EDID data using ACPI. If not found + * poke the given I2C channel to grab EDID data if possible. If found, * attach it to the connector. * * Return: Pointer to valid EDID or NULL if we couldn't find any. @@ -2629,20 +2683,50 @@ EXPORT_SYMBOL(drm_probe_ddc); struct edid *drm_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter) { - struct edid *edid; + struct edid *edid = NULL; if (connector->force == DRM_FORCE_OFF) return NULL; - if (connector->force == DRM_FORCE_UNSPECIFIED && !drm_probe_ddc(adapter)) - return NULL; + if (connector->acpi_edid_allowed) + edid = _drm_do_get_edid(connector, drm_do_probe_acpi_edid, connector, NULL); + + if (!edid) { + if (connector->force == DRM_FORCE_UNSPECIFIED && !drm_probe_ddc(adapter)) + return NULL; + edid = _drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter, NULL); + } - edid = _drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter, NULL); drm_connector_update_edid_property(connector, edid); return edid; } EXPORT_SYMBOL(drm_get_edid); +/** + * drm_edid_read_acpi - get EDID data, if available + * @connector: connector we're probing + * + * Use the BIOS to attempt to grab EDID data if possible. + * + * The returned pointer must be freed using drm_edid_free(). + * + * Return: Pointer to valid EDID or NULL if we couldn't find any. + */ +const struct drm_edid *drm_edid_read_acpi(struct drm_connector *connector) +{ + const struct drm_edid *drm_edid; + + if (connector->force == DRM_FORCE_OFF) + return NULL; + + drm_edid = drm_edid_read_custom(connector, drm_do_probe_acpi_edid, connector); + + /* Note: Do *not* call connector updates here. */ + + return drm_edid; +} +EXPORT_SYMBOL(drm_edid_read_acpi); + /** * drm_edid_read_custom - Read EDID data using given EDID block read function * @connector: Connector to use @@ -2727,10 +2811,11 @@ const struct drm_edid *drm_edid_read_ddc(struct drm_connector *connector, EXPORT_SYMBOL(drm_edid_read_ddc); /** - * drm_edid_read - Read EDID data using connector's I2C adapter + * drm_edid_read - Read EDID data using BIOS or connector's I2C adapter * @connector: Connector to use * - * Read EDID using the connector's I2C adapter. + * Read EDID from BIOS if allowed by connector or by using the connector's + * I2C adapter. * * The EDID may be overridden using debugfs override_edid or firmware EDID * (drm_edid_load_firmware() and drm.edid_firmware parameter), in this priority @@ -2742,10 +2827,18 @@ EXPORT_SYMBOL(drm_edid_read_ddc); */ const struct drm_edid *drm_edid_read(struct drm_connector *connector) { + const struct drm_edid *drm_edid = NULL; + if (drm_WARN_ON(connector->dev, !connector->ddc)) return NULL; - return drm_edid_read_ddc(connector, connector->ddc); + if (connector->acpi_edid_allowed) + drm_edid = drm_edid_read_acpi(connector); + + if (!drm_edid) + drm_edid = drm_edid_read_ddc(connector, connector->ddc); + + return drm_edid; } EXPORT_SYMBOL(drm_edid_read); diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index fe88d7fc6b8f..74ed47f37a69 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -1886,6 +1886,12 @@ struct drm_connector { /** @hdr_sink_metadata: HDR Metadata Information read from sink */ struct hdr_sink_metadata hdr_sink_metadata; + + /** + * @acpi_edid_allowed: Get the EDID from the BIOS, if available. + * This is only applicable to eDP and LVDS displays. + */ + bool acpi_edid_allowed; }; #define obj_to_connector(x) container_of(x, struct drm_connector, base) diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index 7923bc00dc7a..1c1ee927de9c 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -459,5 +459,6 @@ bool drm_edid_is_digital(const struct drm_edid *drm_edid); const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid, int ext_id, int *ext_index); +const struct drm_edid *drm_edid_read_acpi(struct drm_connector *connector); #endif /* __DRM_EDID_H__ */ -- 2.34.1