Commit 2eab8bc0 authored by Takashi Sakamoto's avatar Takashi Sakamoto
Browse files

firewire: core: detect model name for legacy layout of configuration ROM 



As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model_name'
attribute appears in node device, however it is probable to see the other
types of descriptor leaf if the vendor directory includes.

Suggested-by: default avatarAdam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-8-o-takashi@sakamocchi.jp


Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
parent b6a38057

drivers/firewire/core-device.c

+24 −7
Original line number Diff line number Diff line
@@ -317,17 +317,29 @@ static ssize_t show_text_leaf(struct device *dev, 
{

	struct config_rom_attribute *attr =

		container_of(dattr, struct config_rom_attribute, attr);

	const u32 *dir;

	const u32 *directories[] = {NULL, NULL};

	size_t bufsize;

	char dummy_buf[2];

	int ret;

	int i, ret = -ENOENT;



	down_read(&fw_device_rwsem);



	if (is_fw_unit(dev))

		dir = fw_unit(dev)->directory;

	else

		dir = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;

	if (is_fw_unit(dev)) {

		directories[0] = fw_unit(dev)->directory;

	} else {

		const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;

		const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR);



		if (!vendor_directory) {

			directories[0] = root_directory;

		} else {

			// Legacy layout of configuration ROM described in Annex 1 of

			// 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394

			// Trading Association, TA Document 1999027)'.

			directories[0] = root_directory;

			directories[1] = vendor_directory;

		}

	}



	if (buf) {

		bufsize = PAGE_SIZE - 1;
@@ -336,7 +348,12 @@ static ssize_t show_text_leaf(struct device *dev, 
		bufsize = 1;

	}



	ret = fw_csr_string(dir, attr->key, buf, bufsize);

	for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {

		int result = fw_csr_string(directories[i], attr->key, buf, bufsize);

		// Detected.

		if (result >= 0)

			ret = result;

	}



	if (ret >= 0) {

		/* Strip trailing whitespace and add newline. */

drivers/firewire/device-attribute-test.c

+3 −2
Original line number Diff line number Diff line
@@ -206,8 +206,9 @@ static void device_attr_legacy_avc(struct kunit *test) 
	// Descriptor leaf entry for vendor is not found.

	KUNIT_EXPECT_LT(test, show_text_leaf(node_dev, &config_rom_attributes[5].attr, buf), 0);



	// Descriptor leaf entry for model is not found.

	KUNIT_EXPECT_LT(test, show_text_leaf(node_dev, &config_rom_attributes[6].attr, buf), 0);

	// Descriptor leaf entry for model is found.

	KUNIT_EXPECT_GT(test, show_text_leaf(node_dev, &config_rom_attributes[6].attr, buf), 0);

	KUNIT_EXPECT_STREQ(test, buf, "ABCDEFGHIJ\n");



	// For entries in unit 0 directory.