Commit d3581c8e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull firewire updates from Stefan Richter

  - make JMicron JMB38x controllers work with IOMMU-equipped systems

  - IP-over-1394: allow user-configured MTU of up to 4096 bytes

* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire-ohci: work around oversized DMA reads on JMicron controllers
  firewire: net: max MTU off by one
parents ef991796 18877518
......@@ -1480,9 +1480,14 @@ static int fwnet_probe(struct fw_unit *unit,
goto out;
dev->local_fifo = dev->handler.offset;
/*
* default MTU: RFC 2734 cl. 4, RFC 3146 cl. 4
* maximum MTU: RFC 2734 cl. 4.2, fragment encapsulation header's
* maximum possible datagram_size + 1 = 0xfff + 1
*/
net->mtu = 1500U;
net->min_mtu = ETH_MIN_MTU;
net->max_mtu = 0xfff;
net->max_mtu = 4096U;
/* Set our hardware address while we're at it */
ha = (union fwnet_hwaddr *)net->dev_addr;
......
......@@ -1128,7 +1128,13 @@ static int context_add_buffer(struct context *ctx)
return -ENOMEM;
offset = (void *)&desc->buffer - (void *)desc;
desc->buffer_size = PAGE_SIZE - offset;
/*
* Some controllers, like JMicron ones, always issue 0x20-byte DMA reads
* for descriptors, even 0x10-byte ones. This can cause page faults when
* an IOMMU is in use and the oversized read crosses a page boundary.
* Work around this by always leaving at least 0x10 bytes of padding.
*/
desc->buffer_size = PAGE_SIZE - offset - 0x10;
desc->buffer_bus = bus_addr + offset;
desc->used = 0;
......
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