firewire: prevent creation of multiple IR DMA contexts for the same channel

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

diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 4c7cf15..859af71 100644 (file)
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -205,6 +205,7 @@ struct fw_ohci {
 
        u32 it_context_mask;
        struct iso_context *it_context_list;
+       u64 ir_context_channels;
        u32 ir_context_mask;
        struct iso_context *ir_context_list;
 };
@@ -1877,20 +1878,23 @@ static int handle_it_packet(struct context *context,
 }
 
 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
-                                               int type, size_t header_size)
+                               int type, int channel, size_t header_size)
 {
        struct fw_ohci *ohci = fw_ohci(card);
        struct iso_context *ctx, *list;
        descriptor_callback_t callback;
+       u64 *channels, dont_care = ~0ULL;
        u32 *mask, regs;
        unsigned long flags;
        int index, ret = -ENOMEM;
 
        if (type == FW_ISO_CONTEXT_TRANSMIT) {
+               channels = &dont_care;
                mask = &ohci->it_context_mask;
                list = ohci->it_context_list;
                callback = handle_it_packet;
        } else {
+               channels = &ohci->ir_context_channels;
                mask = &ohci->ir_context_mask;
                list = ohci->ir_context_list;
                if (ohci->use_dualbuffer)
@@ -1900,9 +1904,11 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
        }
 
        spin_lock_irqsave(&ohci->lock, flags);
-       index = ffs(*mask) - 1;
-       if (index >= 0)
+       index = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
+       if (index >= 0) {
+               *channels &= ~(1ULL << channel);
                *mask &= ~(1 << index);
+       }
        spin_unlock_irqrestore(&ohci->lock, flags);
 
        if (index < 0)
@@ -2012,6 +2018,7 @@ static void ohci_free_iso_context(struct fw_iso_context *base)
        } else {
                index = ctx - ohci->ir_context_list;
                ohci->ir_context_mask |= 1 << index;
+               ohci->ir_context_channels |= 1ULL << base->channel;
        }
 
        spin_unlock_irqrestore(&ohci->lock, flags);
@@ -2424,6 +2431,7 @@ static int __devinit pci_probe(struct pci_dev *dev,
        ohci->it_context_list = kzalloc(size, GFP_KERNEL);
 
        reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
+       ohci->ir_context_channels = ~0ULL;
        ohci->ir_context_mask = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
        reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
        size = sizeof(struct iso_context) * hweight32(ohci->ir_context_mask);