[PATCH/RFC 2/5] drm/edid: Move functions to avoid forward declaration
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Wed Aug 21 18:50:02 UTC 2019
Move the EDID retrieval functions to the end of the file to avoid
forward declarations. While at it fix a typo in a comment
(s/firmare/firmware/). No functional change is included.
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
drivers/gpu/drm/drm_edid.c | 637 ++++++++++++++++++-------------------
1 file changed, 317 insertions(+), 320 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 7c6bc5183b60..bfcb232b9760 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1340,9 +1340,6 @@ module_param_named(edid_fixup, edid_fixup, int, 0400);
MODULE_PARM_DESC(edid_fixup,
"Minimum number of valid EDID header bytes (0-8, default 6)");
-static void drm_get_displayid(struct drm_connector *connector,
- struct edid *edid);
-
static int drm_edid_block_checksum(const u8 *raw_edid)
{
int i;
@@ -1481,323 +1478,6 @@ bool drm_edid_is_valid(struct edid *edid)
}
EXPORT_SYMBOL(drm_edid_is_valid);
-#define DDC_SEGMENT_ADDR 0x30
-/**
- * drm_do_probe_ddc_edid() - get EDID information via I2C
- * @data: I2C device adapter
- * @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 I2C driver functions.
- *
- * Return: 0 on success or -1 on failure.
- */
-static int
-drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len)
-{
- struct i2c_adapter *adapter = data;
- unsigned char start = block * EDID_LENGTH;
- unsigned char segment = block >> 1;
- unsigned char xfers = segment ? 3 : 2;
- int ret, retries = 5;
-
- /*
- * The core I2C driver will automatically retry the transfer if the
- * adapter reports EAGAIN. However, we find that bit-banging transfers
- * are susceptible to errors under a heavily loaded machine and
- * generate spurious NAKs and timeouts. Retrying the transfer
- * of the individual block a few times seems to overcome this.
- */
- do {
- struct i2c_msg msgs[] = {
- {
- .addr = DDC_SEGMENT_ADDR,
- .flags = 0,
- .len = 1,
- .buf = &segment,
- }, {
- .addr = DDC_ADDR,
- .flags = 0,
- .len = 1,
- .buf = &start,
- }, {
- .addr = DDC_ADDR,
- .flags = I2C_M_RD,
- .len = len,
- .buf = buf,
- }
- };
-
- /*
- * Avoid sending the segment addr to not upset non-compliant
- * DDC monitors.
- */
- ret = i2c_transfer(adapter, &msgs[3 - xfers], xfers);
-
- if (ret == -ENXIO) {
- DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
- adapter->name);
- break;
- }
- } while (ret != xfers && --retries);
-
- return ret == xfers ? 0 : -1;
-}
-
-static void connector_bad_edid(struct drm_connector *connector,
- u8 *edid, int num_blocks)
-{
- int i;
-
- if (connector->bad_edid_counter++ && !(drm_debug & DRM_UT_KMS))
- return;
-
- dev_warn(connector->dev->dev,
- "%s: EDID is invalid:\n",
- connector->name);
- for (i = 0; i < num_blocks; i++) {
- u8 *block = edid + i * EDID_LENGTH;
- char prefix[20];
-
- if (drm_edid_is_zero(block, EDID_LENGTH))
- sprintf(prefix, "\t[%02x] ZERO ", i);
- else if (!drm_edid_block_valid(block, i, false, NULL))
- sprintf(prefix, "\t[%02x] BAD ", i);
- else
- sprintf(prefix, "\t[%02x] GOOD ", i);
-
- print_hex_dump(KERN_WARNING,
- prefix, DUMP_PREFIX_NONE, 16, 1,
- block, EDID_LENGTH, false);
- }
-}
-
-/* Get override or firmware EDID */
-static struct edid *drm_get_override_edid(struct drm_connector *connector)
-{
- struct edid *override = NULL;
-
- if (connector->override_edid)
- override = drm_edid_duplicate(connector->edid_blob_ptr->data);
-
- if (!override)
- override = drm_load_edid_firmware(connector);
-
- return IS_ERR(override) ? NULL : override;
-}
-
-/**
- * drm_add_override_edid_modes - add modes from override/firmware EDID
- * @connector: connector we're probing
- *
- * Add modes from the override/firmware EDID, if available. Only to be used from
- * drm_helper_probe_single_connector_modes() as a fallback for when DDC probe
- * failed during drm_get_edid() and caused the override/firmware EDID to be
- * skipped.
- *
- * Return: The number of modes added or 0 if we couldn't find any.
- */
-int drm_add_override_edid_modes(struct drm_connector *connector)
-{
- struct edid *override;
- int num_modes = 0;
-
- override = drm_get_override_edid(connector);
- if (override) {
- drm_connector_update_edid_property(connector, override);
- num_modes = drm_add_edid_modes(connector, override);
- kfree(override);
-
- DRM_DEBUG_KMS("[CONNECTOR:%d:%s] adding %d modes via fallback override/firmware EDID\n",
- connector->base.id, connector->name, num_modes);
- }
-
- return num_modes;
-}
-EXPORT_SYMBOL(drm_add_override_edid_modes);
-
-/**
- * drm_do_get_edid - get EDID data using a custom EDID block read function
- * @connector: connector we're probing
- * @get_edid_block: EDID block read function
- * @data: private data passed to the block read function
- *
- * When the I2C adapter connected to the DDC bus is hidden behind a device that
- * exposes a different interface to read EDID blocks this function can be used
- * to get EDID data using a custom block read function.
- *
- * As in the general case the DDC bus is accessible by the kernel at the I2C
- * level, drivers must make all reasonable efforts to expose it as an I2C
- * adapter and use drm_get_edid() instead of abusing this function.
- *
- * The EDID may be overridden using debugfs override_edid or firmare EDID
- * (drm_load_edid_firmware() and drm.edid_firmware parameter), in this priority
- * order. Having either of them bypasses actual EDID reads.
- *
- * Return: Pointer to valid EDID or NULL if we couldn't find any.
- */
-struct edid *drm_do_get_edid(struct drm_connector *connector,
- int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
- size_t len),
- void *data)
-{
- int i, j = 0, valid_extensions = 0;
- u8 *edid, *new;
- struct edid *override;
-
- override = drm_get_override_edid(connector);
- if (override)
- return override;
-
- if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
- return NULL;
-
- /* base block fetch */
- for (i = 0; i < 4; i++) {
- if (get_edid_block(data, edid, 0, EDID_LENGTH))
- goto out;
- if (drm_edid_block_valid(edid, 0, false,
- &connector->edid_corrupt))
- break;
- if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
- connector->null_edid_counter++;
- goto carp;
- }
- }
- if (i == 4)
- goto carp;
-
- /* if there's no extensions, we're done */
- valid_extensions = edid[0x7e];
- if (valid_extensions == 0)
- return (struct edid *)edid;
-
- new = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
- if (!new)
- goto out;
- edid = new;
-
- for (j = 1; j <= edid[0x7e]; j++) {
- u8 *block = edid + j * EDID_LENGTH;
-
- for (i = 0; i < 4; i++) {
- if (get_edid_block(data, block, j, EDID_LENGTH))
- goto out;
- if (drm_edid_block_valid(block, j, false, NULL))
- break;
- }
-
- if (i == 4)
- valid_extensions--;
- }
-
- if (valid_extensions != edid[0x7e]) {
- u8 *base;
-
- connector_bad_edid(connector, edid, edid[0x7e] + 1);
-
- edid[EDID_LENGTH-1] += edid[0x7e] - valid_extensions;
- edid[0x7e] = valid_extensions;
-
- new = kmalloc_array(valid_extensions + 1, EDID_LENGTH,
- GFP_KERNEL);
- if (!new)
- goto out;
-
- base = new;
- for (i = 0; i <= edid[0x7e]; i++) {
- u8 *block = edid + i * EDID_LENGTH;
-
- if (!drm_edid_block_valid(block, i, false, NULL))
- continue;
-
- memcpy(base, block, EDID_LENGTH);
- base += EDID_LENGTH;
- }
-
- kfree(edid);
- edid = new;
- }
-
- return (struct edid *)edid;
-
-carp:
- connector_bad_edid(connector, edid, 1);
-out:
- kfree(edid);
- return NULL;
-}
-EXPORT_SYMBOL_GPL(drm_do_get_edid);
-
-/**
- * drm_probe_ddc() - probe DDC presence
- * @adapter: I2C adapter to probe
- *
- * Return: True on success, false on failure.
- */
-bool
-drm_probe_ddc(struct i2c_adapter *adapter)
-{
- unsigned char out;
-
- return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
-}
-EXPORT_SYMBOL(drm_probe_ddc);
-
-/**
- * drm_get_edid - get EDID data, if available
- * @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,
- * attach it to the connector.
- *
- * Return: Pointer to valid EDID or NULL if we couldn't find any.
- */
-struct edid *drm_get_edid(struct drm_connector *connector,
- struct i2c_adapter *adapter)
-{
- struct edid *edid;
-
- if (connector->force == DRM_FORCE_OFF)
- return NULL;
-
- if (connector->force == DRM_FORCE_UNSPECIFIED && !drm_probe_ddc(adapter))
- return NULL;
-
- edid = drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter);
- if (edid)
- drm_get_displayid(connector, edid);
- return edid;
-}
-EXPORT_SYMBOL(drm_get_edid);
-
-/**
- * drm_get_edid_switcheroo - get EDID data for a vga_switcheroo output
- * @connector: connector we're probing
- * @adapter: I2C adapter to use for DDC
- *
- * Wrapper around drm_get_edid() for laptops with dual GPUs using one set of
- * outputs. The wrapper adds the requisite vga_switcheroo calls to temporarily
- * switch DDC to the GPU which is retrieving EDID.
- *
- * Return: Pointer to valid EDID or %NULL if we couldn't find any.
- */
-struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
- struct i2c_adapter *adapter)
-{
- struct pci_dev *pdev = connector->dev->pdev;
- struct edid *edid;
-
- vga_switcheroo_lock_ddc(pdev);
- edid = drm_get_edid(connector, adapter);
- vga_switcheroo_unlock_ddc(pdev);
-
- return edid;
-}
-EXPORT_SYMBOL(drm_get_edid_switcheroo);
-
/**
* drm_edid_duplicate - duplicate an EDID and the extensions
* @edid: EDID to duplicate
@@ -5490,3 +5170,320 @@ static void drm_get_displayid(struct drm_connector *connector,
connector->tile_group = NULL;
}
}
+
+#define DDC_SEGMENT_ADDR 0x30
+/**
+ * drm_do_probe_ddc_edid() - get EDID information via I2C
+ * @data: I2C device adapter
+ * @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 I2C driver functions.
+ *
+ * Return: 0 on success or -1 on failure.
+ */
+static int
+drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len)
+{
+ struct i2c_adapter *adapter = data;
+ unsigned char start = block * EDID_LENGTH;
+ unsigned char segment = block >> 1;
+ unsigned char xfers = segment ? 3 : 2;
+ int ret, retries = 5;
+
+ /*
+ * The core I2C driver will automatically retry the transfer if the
+ * adapter reports EAGAIN. However, we find that bit-banging transfers
+ * are susceptible to errors under a heavily loaded machine and
+ * generate spurious NAKs and timeouts. Retrying the transfer
+ * of the individual block a few times seems to overcome this.
+ */
+ do {
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DDC_SEGMENT_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &segment,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &start,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = buf,
+ }
+ };
+
+ /*
+ * Avoid sending the segment addr to not upset non-compliant
+ * DDC monitors.
+ */
+ ret = i2c_transfer(adapter, &msgs[3 - xfers], xfers);
+
+ if (ret == -ENXIO) {
+ DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
+ adapter->name);
+ break;
+ }
+ } while (ret != xfers && --retries);
+
+ return ret == xfers ? 0 : -1;
+}
+
+static void connector_bad_edid(struct drm_connector *connector,
+ u8 *edid, int num_blocks)
+{
+ int i;
+
+ if (connector->bad_edid_counter++ && !(drm_debug & DRM_UT_KMS))
+ return;
+
+ dev_warn(connector->dev->dev,
+ "%s: EDID is invalid:\n",
+ connector->name);
+ for (i = 0; i < num_blocks; i++) {
+ u8 *block = edid + i * EDID_LENGTH;
+ char prefix[20];
+
+ if (drm_edid_is_zero(block, EDID_LENGTH))
+ sprintf(prefix, "\t[%02x] ZERO ", i);
+ else if (!drm_edid_block_valid(block, i, false, NULL))
+ sprintf(prefix, "\t[%02x] BAD ", i);
+ else
+ sprintf(prefix, "\t[%02x] GOOD ", i);
+
+ print_hex_dump(KERN_WARNING,
+ prefix, DUMP_PREFIX_NONE, 16, 1,
+ block, EDID_LENGTH, false);
+ }
+}
+
+/* Get override or firmware EDID */
+static struct edid *drm_get_override_edid(struct drm_connector *connector)
+{
+ struct edid *override = NULL;
+
+ if (connector->override_edid)
+ override = drm_edid_duplicate(connector->edid_blob_ptr->data);
+
+ if (!override)
+ override = drm_load_edid_firmware(connector);
+
+ return IS_ERR(override) ? NULL : override;
+}
+
+/**
+ * drm_add_override_edid_modes - add modes from override/firmware EDID
+ * @connector: connector we're probing
+ *
+ * Add modes from the override/firmware EDID, if available. Only to be used from
+ * drm_helper_probe_single_connector_modes() as a fallback for when DDC probe
+ * failed during drm_get_edid() and caused the override/firmware EDID to be
+ * skipped.
+ *
+ * Return: The number of modes added or 0 if we couldn't find any.
+ */
+int drm_add_override_edid_modes(struct drm_connector *connector)
+{
+ struct edid *override;
+ int num_modes = 0;
+
+ override = drm_get_override_edid(connector);
+ if (override) {
+ drm_connector_update_edid_property(connector, override);
+ num_modes = drm_add_edid_modes(connector, override);
+ kfree(override);
+
+ DRM_DEBUG_KMS("[CONNECTOR:%d:%s] adding %d modes via fallback override/firmware EDID\n",
+ connector->base.id, connector->name, num_modes);
+ }
+
+ return num_modes;
+}
+EXPORT_SYMBOL(drm_add_override_edid_modes);
+
+/**
+ * drm_do_get_edid - get EDID data using a custom EDID block read function
+ * @connector: connector we're probing
+ * @get_edid_block: EDID block read function
+ * @data: private data passed to the block read function
+ *
+ * When the I2C adapter connected to the DDC bus is hidden behind a device that
+ * exposes a different interface to read EDID blocks this function can be used
+ * to get EDID data using a custom block read function.
+ *
+ * As in the general case the DDC bus is accessible by the kernel at the I2C
+ * level, drivers must make all reasonable efforts to expose it as an I2C
+ * adapter and use drm_get_edid() instead of abusing this function.
+ *
+ * The EDID may be overridden using debugfs override_edid or firmware EDID
+ * (drm_load_edid_firmware() and drm.edid_firmware parameter), in this priority
+ * order. Having either of them bypasses actual EDID reads.
+ *
+ * Return: Pointer to valid EDID or NULL if we couldn't find any.
+ */
+struct edid *drm_do_get_edid(struct drm_connector *connector,
+ int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
+ size_t len),
+ void *data)
+{
+ int i, j = 0, valid_extensions = 0;
+ u8 *edid, *new;
+ struct edid *override;
+
+ override = drm_get_override_edid(connector);
+ if (override)
+ return override;
+
+ if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
+ return NULL;
+
+ /* base block fetch */
+ for (i = 0; i < 4; i++) {
+ if (get_edid_block(data, edid, 0, EDID_LENGTH))
+ goto out;
+ if (drm_edid_block_valid(edid, 0, false,
+ &connector->edid_corrupt))
+ break;
+ if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
+ connector->null_edid_counter++;
+ goto carp;
+ }
+ }
+ if (i == 4)
+ goto carp;
+
+ /* if there's no extensions, we're done */
+ valid_extensions = edid[0x7e];
+ if (valid_extensions == 0)
+ return (struct edid *)edid;
+
+ new = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
+ if (!new)
+ goto out;
+ edid = new;
+
+ for (j = 1; j <= edid[0x7e]; j++) {
+ u8 *block = edid + j * EDID_LENGTH;
+
+ for (i = 0; i < 4; i++) {
+ if (get_edid_block(data, block, j, EDID_LENGTH))
+ goto out;
+ if (drm_edid_block_valid(block, j, false, NULL))
+ break;
+ }
+
+ if (i == 4)
+ valid_extensions--;
+ }
+
+ if (valid_extensions != edid[0x7e]) {
+ u8 *base;
+
+ connector_bad_edid(connector, edid, edid[0x7e] + 1);
+
+ edid[EDID_LENGTH-1] += edid[0x7e] - valid_extensions;
+ edid[0x7e] = valid_extensions;
+
+ new = kmalloc_array(valid_extensions + 1, EDID_LENGTH,
+ GFP_KERNEL);
+ if (!new)
+ goto out;
+
+ base = new;
+ for (i = 0; i <= edid[0x7e]; i++) {
+ u8 *block = edid + i * EDID_LENGTH;
+
+ if (!drm_edid_block_valid(block, i, false, NULL))
+ continue;
+
+ memcpy(base, block, EDID_LENGTH);
+ base += EDID_LENGTH;
+ }
+
+ kfree(edid);
+ edid = new;
+ }
+
+ return (struct edid *)edid;
+
+carp:
+ connector_bad_edid(connector, edid, 1);
+out:
+ kfree(edid);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(drm_do_get_edid);
+
+/**
+ * drm_probe_ddc() - probe DDC presence
+ * @adapter: I2C adapter to probe
+ *
+ * Return: True on success, false on failure.
+ */
+bool
+drm_probe_ddc(struct i2c_adapter *adapter)
+{
+ unsigned char out;
+
+ return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
+}
+EXPORT_SYMBOL(drm_probe_ddc);
+
+/**
+ * drm_get_edid - get EDID data, if available
+ * @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,
+ * attach it to the connector.
+ *
+ * Return: Pointer to valid EDID or NULL if we couldn't find any.
+ */
+struct edid *drm_get_edid(struct drm_connector *connector,
+ struct i2c_adapter *adapter)
+{
+ struct edid *edid;
+
+ if (connector->force == DRM_FORCE_OFF)
+ return NULL;
+
+ if (connector->force == DRM_FORCE_UNSPECIFIED && !drm_probe_ddc(adapter))
+ return NULL;
+
+ edid = drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter);
+ if (edid)
+ drm_get_displayid(connector, edid);
+ return edid;
+}
+EXPORT_SYMBOL(drm_get_edid);
+
+/**
+ * drm_get_edid_switcheroo - get EDID data for a vga_switcheroo output
+ * @connector: connector we're probing
+ * @adapter: I2C adapter to use for DDC
+ *
+ * Wrapper around drm_get_edid() for laptops with dual GPUs using one set of
+ * outputs. The wrapper adds the requisite vga_switcheroo calls to temporarily
+ * switch DDC to the GPU which is retrieving EDID.
+ *
+ * Return: Pointer to valid EDID or %NULL if we couldn't find any.
+ */
+struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
+ struct i2c_adapter *adapter)
+{
+ struct pci_dev *pdev = connector->dev->pdev;
+ struct edid *edid;
+
+ vga_switcheroo_lock_ddc(pdev);
+ edid = drm_get_edid(connector, adapter);
+ vga_switcheroo_unlock_ddc(pdev);
+
+ return edid;
+}
+EXPORT_SYMBOL(drm_get_edid_switcheroo);
--
Regards,
Laurent Pinchart
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