Commit 5ae73518 authored Mar 19, 2010 by Stefan Richter

firewire: core: fix Model_ID in modalias



The modalias string of devices that represent units on a FireWire node
did not show Module_ID entries within unit directories.  This was
because firewire-core searched only the root directory of the
configuration ROM for a Model_ID entry.

We now search first the root directory, then the unit directory.  IOW
honor a unit directory's Model_ID if present, otherwise fall back to the
root directory's model ID (if present).

Furthermore, apply the same change to Vendor_ID.  This had the same
issue but it was less apparent because most devices provide Vendor_ID
only in the root directory.

And finally, also use this strategy for the remaining two IDs in the
modalias, Specifier_ID and Version.  It does not actually make sense to
look for them elsewhere than in the unit directory because they are
mandatory there.  However, a uniform search order simplifies the
implementation and has no adverse affect in practice.

Side notes:
  - The older counterpart of this, nodemgr.c of ieee1394, looked for
    Vendor_ID first in the root directory, then in the unit directory,
    and for Model_ID only in the unit directory.
  - There is a single mainline driver which requires Vendor_ID and
    Model_ID --- the firedtv driver.  This one worked because FireDTVs
    provide Vendor_ID in the root directory and Model_ID identically in
    root directory and unit directory.
  - Apart from firedtv, there are currently no drivers known to me
    (including userspace drivers) that look at the Vendor_ID or Model_ID
    of the modalias.

Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

parent 8301b91b

drivers/firewire/core-device.c

+14 −26

Original line number	Diff line number	Diff line
		@@ -180,44 +180,32 @@ static int fw_unit_match(struct device dev, struct device_driver drv)
		return 0;
		}

		static int get_modalias(struct fw_unit unit, char buffer, size_t buffer_size)
		static void get_modalias_ids(const u32 directory, int id)
		{
		struct fw_device *device = fw_parent_device(unit);
		struct fw_csr_iterator ci;

		int key, value;
		int vendor = 0;
		int model = 0;
		int specifier_id = 0;
		int version = 0;

		fw_csr_iterator_init(&ci, &device->config_rom[5]);
		fw_csr_iterator_init(&ci, directory);
		while (fw_csr_iterator_next(&ci, &key, &value)) {
		switch (key) {
		case CSR_VENDOR:
		vendor = value;
		break;
		case CSR_MODEL:
		model = value;
		break;
		}
		case CSR_VENDOR: id[0] = value; break;
		case CSR_MODEL: id[1] = value; break;
		case CSR_SPECIFIER_ID: id[2] = value; break;
		case CSR_VERSION: id[3] = value; break;
		}

		fw_csr_iterator_init(&ci, unit->directory);
		while (fw_csr_iterator_next(&ci, &key, &value)) {
		switch (key) {
		case CSR_SPECIFIER_ID:
		specifier_id = value;
		break;
		case CSR_VERSION:
		version = value;
		break;
		}
		}

		static int get_modalias(struct fw_unit unit, char buffer, size_t buffer_size)
		{
		int id[] = {0, 0, 0, 0};

		get_modalias_ids(&fw_parent_device(unit)->config_rom[5], id);
		get_modalias_ids(unit->directory, id);

		return snprintf(buffer, buffer_size,
		"ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
		vendor, model, specifier_id, version);
		id[0], id[1], id[2], id[3]);
		}

		static int fw_unit_uevent(struct device dev, struct kobj_uevent_env env)