Merge tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull IEEE 1394 (FireWire) subsystem updates from Stefan Richter:

 - Fix mismatch between DMA mapping direction (was wrong) and DMA
   synchronization direction (was correct) of isochronous reception
   buffers of userspace drivers if vma-mapped for R/W access.  For
   example, libdc1394 was affected.

 - more consistent retry stategy in device discovery/ rediscovery, and
   improved failure diagnostics

 - various small cleanups, e.g. use SCSI layer's DMA mapping API in
   firewire-sbp2

* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: sbp2: document the absence of alignment requirements
  firewire: sbp2: remove superfluous blk_queue_max_segment_size() call
  firewire: sbp2: use scsi_dma_(un)map
  firewire: sbp2: give correct DMA device to scsi framework
  firewire: core: fw_device_refresh(): clean up error handling
  firewire: core: log config rom reading errors
  firewire: core: log error in case of failed bus manager lock
  firewire: move rcode_string() to core
  firewire: core: improve reread_config_rom() interface
  firewire: core: wait for inaccessible devices after bus reset
  firewire: ohci: omit spinlock IRQ flags where possible
  firewire: ohci: correct signedness of a local variable
  firewire: core: fix DMA mapping direction
  firewire: use module_pci_driver

1 files changed, 57 insertions, 59 deletions

diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 68109e9bb04e..4d460ef87161 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -481,6 +481,7 @@ static int read_rom(struct fw_device *device,
  * generation changes under us, read_config_rom will fail and get retried.
  * It's better to start all over in this case because the node from which we
  * are reading the ROM may have changed the ROM during the reset.
+ * Returns either a result code or a negative error code.
  */
 static int read_config_rom(struct fw_device *device, int generation)
 {
@@ -488,7 +489,7 @@ static int read_config_rom(struct fw_device *device, int generation)
 	const u32 *old_rom, *new_rom;
 	u32 *rom, *stack;
 	u32 sp, key;
-	int i, end, length, ret = -1;
+	int i, end, length, ret;
 
 	rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 		      sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
@@ -502,18 +503,21 @@ static int read_config_rom(struct fw_device *device, int generation)
 
 	/* First read the bus info block. */
 	for (i = 0; i < 5; i++) {
-		if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
+		ret = read_rom(device, generation, i, &rom[i]);
+		if (ret != RCODE_COMPLETE)
 			goto out;
 		/*
-		 * As per IEEE1212 7.2, during power-up, devices can
+		 * As per IEEE1212 7.2, during initialization, devices can
 		 * reply with a 0 for the first quadlet of the config
 		 * rom to indicate that they are booting (for example,
 		 * if the firmware is on the disk of a external
 		 * harddisk).  In that case we just fail, and the
 		 * retry mechanism will try again later.
 		 */
-		if (i == 0 && rom[i] == 0)
+		if (i == 0 && rom[i] == 0) {
+			ret = RCODE_BUSY;
 			goto out;
+		}
 	}
 
 	device->max_speed = device->node->max_speed;
@@ -563,11 +567,14 @@ static int read_config_rom(struct fw_device *device, int generation)
 		 */
 		key = stack[--sp];
 		i = key & 0xffffff;
-		if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE))
+		if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
+			ret = -ENXIO;
 			goto out;
+		}
 
 		/* Read header quadlet for the block to get the length. */
-		if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
+		ret = read_rom(device, generation, i, &rom[i]);
+		if (ret != RCODE_COMPLETE)
 			goto out;
 		end = i + (rom[i] >> 16) + 1;
 		if (end > MAX_CONFIG_ROM_SIZE) {
@@ -590,8 +597,8 @@ static int read_config_rom(struct fw_device *device, int generation)
 		 * it references another block, and push it in that case.
 		 */
 		for (; i < end; i++) {
-			if (read_rom(device, generation, i, &rom[i]) !=
-			    RCODE_COMPLETE)
+			ret = read_rom(device, generation, i, &rom[i]);
+			if (ret != RCODE_COMPLETE)
 				goto out;
 
 			if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
@@ -619,8 +626,10 @@ static int read_config_rom(struct fw_device *device, int generation)
 
 	old_rom = device->config_rom;
 	new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
-	if (new_rom == NULL)
+	if (new_rom == NULL) {
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	down_write(&fw_device_rwsem);
 	device->config_rom = new_rom;
@@ -628,7 +637,7 @@ static int read_config_rom(struct fw_device *device, int generation)
 	up_write(&fw_device_rwsem);
 
 	kfree(old_rom);
-	ret = 0;
+	ret = RCODE_COMPLETE;
 	device->max_rec	= rom[2] >> 12 & 0xf;
 	device->cmc	= rom[2] >> 30 & 1;
 	device->irmc	= rom[2] >> 31 & 1;
@@ -967,15 +976,17 @@ static void fw_device_init(struct work_struct *work)
 	 * device.
 	 */
 
-	if (read_config_rom(device, device->generation) < 0) {
+	ret = read_config_rom(device, device->generation);
+	if (ret != RCODE_COMPLETE) {
 		if (device->config_rom_retries < MAX_RETRIES &&
 		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 			device->config_rom_retries++;
 			fw_schedule_device_work(device, RETRY_DELAY);
 		} else {
 			if (device->node->link_on)
-				fw_notice(card, "giving up on Config ROM for node id %x\n",
-					  device->node_id);
+				fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
+					  device->node_id,
+					  fw_rcode_string(ret));
 			if (device->node == card->root_node)
 				fw_schedule_bm_work(card, 0);
 			fw_device_release(&device->device);
@@ -1069,31 +1080,30 @@ static void fw_device_init(struct work_struct *work)
 	put_device(&device->device);	/* our reference */
 }
 
-enum {
-	REREAD_BIB_ERROR,
-	REREAD_BIB_GONE,
-	REREAD_BIB_UNCHANGED,
-	REREAD_BIB_CHANGED,
-};
-
 /* Reread and compare bus info block and header of root directory */
-static int reread_config_rom(struct fw_device *device, int generation)
+static int reread_config_rom(struct fw_device *device, int generation,
+			     bool *changed)
 {
 	u32 q;
-	int i;
+	int i, rcode;
 
 	for (i = 0; i < 6; i++) {
-		if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
-			return REREAD_BIB_ERROR;
+		rcode = read_rom(device, generation, i, &q);
+		if (rcode != RCODE_COMPLETE)
+			return rcode;
 
 		if (i == 0 && q == 0)
-			return REREAD_BIB_GONE;
+			/* inaccessible (see read_config_rom); retry later */
+			return RCODE_BUSY;
 
-		if (q != device->config_rom[i])
-			return REREAD_BIB_CHANGED;
+		if (q != device->config_rom[i]) {
+			*changed = true;
+			return RCODE_COMPLETE;
+		}
 	}
 
-	return REREAD_BIB_UNCHANGED;
+	*changed = false;
+	return RCODE_COMPLETE;
 }
 
 static void fw_device_refresh(struct work_struct *work)
@@ -1101,23 +1111,14 @@ static void fw_device_refresh(struct work_struct *work)
 	struct fw_device *device =
 		container_of(work, struct fw_device, work.work);
 	struct fw_card *card = device->card;
-	int node_id = device->node_id;
-
-	switch (reread_config_rom(device, device->generation)) {
-	case REREAD_BIB_ERROR:
-		if (device->config_rom_retries < MAX_RETRIES / 2 &&
-		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
-			device->config_rom_retries++;
-			fw_schedule_device_work(device, RETRY_DELAY / 2);
-
-			return;
-		}
-		goto give_up;
+	int ret, node_id = device->node_id;
+	bool changed;
 
-	case REREAD_BIB_GONE:
-		goto gone;
+	ret = reread_config_rom(device, device->generation, &changed);
+	if (ret != RCODE_COMPLETE)
+		goto failed_config_rom;
 
-	case REREAD_BIB_UNCHANGED:
+	if (!changed) {
 		if (atomic_cmpxchg(&device->state,
 				   FW_DEVICE_INITIALIZING,
 				   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
@@ -1126,9 +1127,6 @@ static void fw_device_refresh(struct work_struct *work)
 		fw_device_update(work);
 		device->config_rom_retries = 0;
 		goto out;
-
-	case REREAD_BIB_CHANGED:
-		break;
 	}
 
 	/*
@@ -1137,16 +1135,9 @@ static void fw_device_refresh(struct work_struct *work)
 	 */
 	device_for_each_child(&device->device, NULL, shutdown_unit);
 
-	if (read_config_rom(device, device->generation) < 0) {
-		if (device->config_rom_retries < MAX_RETRIES &&
-		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
-			device->config_rom_retries++;
-			fw_schedule_device_work(device, RETRY_DELAY);
-
-			return;
-		}
-		goto give_up;
-	}
+	ret = read_config_rom(device, device->generation);
+	if (ret != RCODE_COMPLETE)
+		goto failed_config_rom;
 
 	fw_device_cdev_update(device);
 	create_units(device);
@@ -1163,9 +1154,16 @@ static void fw_device_refresh(struct work_struct *work)
 	device->config_rom_retries = 0;
 	goto out;
 
- give_up:
-	fw_notice(card, "giving up on refresh of device %s\n",
-		  dev_name(&device->device));
+ failed_config_rom:
+	if (device->config_rom_retries < MAX_RETRIES &&
+	    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
+		device->config_rom_retries++;
+		fw_schedule_device_work(device, RETRY_DELAY);
+		return;
+	}
+
+	fw_notice(card, "giving up on refresh of device %s: %s\n",
+		  dev_name(&device->device), fw_rcode_string(ret));
  gone:
 	atomic_set(&device->state, FW_DEVICE_GONE);
 	PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);