firewire: Fix for broken configrom updates in quick succession

[pandora-kernel.git] / drivers / firewire / ohci.c

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index c739436..23d1468 100644 (file)
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1329,21 +1329,8 @@ static int at_context_queue_packet(struct context *ctx,
                                     DESCRIPTOR_IRQ_ALWAYS |
                                     DESCRIPTOR_BRANCH_ALWAYS);
 
-       /*
-        * If the controller and packet generations don't match, we need to
-        * bail out and try again.  If IntEvent.busReset is set, the AT context
-        * is halted, so appending to the context and trying to run it is
-        * futile.  Most controllers do the right thing and just flush the AT
-        * queue (per section 7.2.3.2 of the OHCI 1.1 specification), but
-        * some controllers (like a JMicron JMB381 PCI-e) misbehave and wind
-        * up stalling out.  So we just bail out in software and try again
-        * later, and everyone is happy.
-        * FIXME: Test of IntEvent.busReset may no longer be necessary since we
-        *        flush AT queues in bus_reset_tasklet.
-        * FIXME: Document how the locking works.
-        */
-       if (ohci->generation != packet->generation ||
-           reg_read(ohci, OHCI1394_IntEventSet) & OHCI1394_busReset) {
+       /* FIXME: Document how the locking works. */
+       if (ohci->generation != packet->generation) {
                if (packet->payload_mapped)
                        dma_unmap_single(ohci->card.device, payload_bus,
                                         packet->payload_length, DMA_TO_DEVICE);
@@ -2212,7 +2199,6 @@ static int ohci_set_config_rom(struct fw_card *card,
 {
        struct fw_ohci *ohci;
        unsigned long flags;
-       int ret = -EBUSY;
        __be32 *next_config_rom;
        dma_addr_t uninitialized_var(next_config_rom_bus);
 
@@ -2253,22 +2239,37 @@ static int ohci_set_config_rom(struct fw_card *card,
 
        spin_lock_irqsave(&ohci->lock, flags);
 
+       /*
+        * If there is not an already pending config_rom update,
+        * push our new allocation into the ohci->next_config_rom
+        * and then mark the local variable as null so that we
+        * won't deallocate the new buffer.
+        *
+        * OTOH, if there is a pending config_rom update, just
+        * use that buffer with the new config_rom data, and
+        * let this routine free the unused DMA allocation.
+        */
+
        if (ohci->next_config_rom == NULL) {
                ohci->next_config_rom = next_config_rom;
                ohci->next_config_rom_bus = next_config_rom_bus;
+               next_config_rom = NULL;
+       }
 
-               copy_config_rom(ohci->next_config_rom, config_rom, length);
+       copy_config_rom(ohci->next_config_rom, config_rom, length);
 
-               ohci->next_header = config_rom[0];
-               ohci->next_config_rom[0] = 0;
+       ohci->next_header = config_rom[0];
+       ohci->next_config_rom[0] = 0;
 
-               reg_write(ohci, OHCI1394_ConfigROMmap,
-                         ohci->next_config_rom_bus);
-               ret = 0;
-       }
+       reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
 
        spin_unlock_irqrestore(&ohci->lock, flags);
 
+       /* If we didn't use the DMA allocation, delete it. */
+       if (next_config_rom != NULL)
+               dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+                                 next_config_rom, next_config_rom_bus);
+
        /*
         * Now initiate a bus reset to have the changes take
         * effect. We clean up the old config rom memory and DMA
@@ -2276,13 +2277,10 @@ static int ohci_set_config_rom(struct fw_card *card,
         * controller could need to access it before the bus reset
         * takes effect.
         */
-       if (ret == 0)
-               fw_schedule_bus_reset(&ohci->card, true, true);
-       else
-               dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-                                 next_config_rom, next_config_rom_bus);
 
-       return ret;
+       fw_schedule_bus_reset(&ohci->card, true, true);
+
+       return 0;
 }
 
 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
@@ -2706,6 +2704,10 @@ static int ohci_start_iso(struct fw_iso_context *base,
        u32 control = IR_CONTEXT_ISOCH_HEADER, match;
        int index;
 
+       /* the controller cannot start without any queued packets */
+       if (ctx->context.last->branch_address == 0)
+               return -ENODATA;
+
        switch (ctx->base.type) {
        case FW_ISO_CONTEXT_TRANSMIT:
                index = ctx - ohci->it_context_list;
@@ -2764,6 +2766,7 @@ static int ohci_stop_iso(struct fw_iso_context *base)
        }
        flush_writes(ohci);
        context_stop(&ctx->context);
+       tasklet_kill(&ctx->context.tasklet);
 
        return 0;
 }
@@ -3317,7 +3320,7 @@ static int __devinit pci_probe(struct pci_dev *dev,
  fail_disable:
        pci_disable_device(dev);
  fail_free:
-       kfree(&ohci->card);
+       kfree(ohci);
        pmac_ohci_off(dev);
  fail:
        if (err == -ENOMEM)
@@ -3361,7 +3364,7 @@ static void pci_remove(struct pci_dev *dev)
        pci_iounmap(dev, ohci->registers);
        pci_release_region(dev, 0);
        pci_disable_device(dev);
-       kfree(&ohci->card);
+       kfree(ohci);
        pmac_ohci_off(dev);
 
        fw_notify("Removed fw-ohci device.\n");