Commit eaf76e0d authored by Stefan Richter's avatar Stefan Richter
Browse files

firewire: sbp2: provide fallback if mgt_ORB_timeout is missing 



The Unit_Characteristics entry of an SBP-2 unit directory is not
mandatory as far as I can tell.  If it is missing, we would probably
fail to log in into the target because firewire-sbp2 would not wait for
status after it sent the login request.

The fix moves the cleanup of tgt->mgt_orb_timeout into a place where it
is executed exactly once before login, rather than 0..n times depending
on the target's config ROM.  With targets with one or more
Unit_Characteristics entries, the result is the same as before.

Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 544df55d

drivers/firewire/sbp2.c

+19 −20
Original line number Diff line number Diff line
@@ -188,13 +188,6 @@ static struct fw_device *target_device(struct sbp2_target *tgt) 
/* Impossible login_id, to detect logout attempt before successful login */

#define INVALID_LOGIN_ID 0x10000



/*

 * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be

 * provided in the config rom. Most devices do provide a value, which

 * we'll use for login management orbs, but with some sane limits.

 */

#define SBP2_MIN_LOGIN_ORB_TIMEOUT	5000U	/* Timeout in ms */

#define SBP2_MAX_LOGIN_ORB_TIMEOUT	40000U	/* Timeout in ms */

#define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */

#define SBP2_ORB_NULL			0x80000000

#define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
@@ -1034,7 +1027,6 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory, 
{

	struct fw_csr_iterator ci;

	int key, value;

	unsigned int timeout;



	fw_csr_iterator_init(&ci, directory);

	while (fw_csr_iterator_next(&ci, &key, &value)) {
@@ -1059,17 +1051,7 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory, 


		case SBP2_CSR_UNIT_CHARACTERISTICS:

			/* the timeout value is stored in 500ms units */

			timeout = ((unsigned int) value >> 8 & 0xff) * 500;

			timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);

			tgt->mgt_orb_timeout =

				  min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);



			if (timeout > tgt->mgt_orb_timeout)

				fw_notify("%s: config rom contains %ds "

					  "management ORB timeout, limiting "

					  "to %ds\n", tgt->bus_id,

					  timeout / 1000,

					  tgt->mgt_orb_timeout / 1000);

			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;

			break;



		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
@@ -1087,6 +1069,22 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory, 
	return 0;

}



/*

 * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be

 * provided in the config rom. Most devices do provide a value, which

 * we'll use for login management orbs, but with some sane limits.

 */

static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)

{

	unsigned int timeout = tgt->mgt_orb_timeout;



	if (timeout > 40000)

		fw_notify("%s: %ds mgt_ORB_timeout limited to 40s\n",

			  tgt->bus_id, timeout / 1000);



	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);

}



static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,

				  u32 firmware_revision)

{
@@ -1171,6 +1169,7 @@ static int sbp2_probe(struct device *dev) 
			       &firmware_revision) < 0)

		goto fail_tgt_put;



	sbp2_clamp_management_orb_timeout(tgt);

	sbp2_init_workarounds(tgt, model, firmware_revision);



	/*

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