2008-07-22 16:41:30

by Stefan Richter

[permalink] [raw]
Subject: [PATCH] firewire: fw-ohci: TSB43AB22/A dualbuffer workaround

Isochronous reception in dualbuffer is reportedly broken with
TI TSB43AB22A on x86-64. Descriptor addresses above 2G have been
determined as the trigger:
https://bugzilla.redhat.com/show_bug.cgi?id=435550

Two fixes are possible:
- pci_set_consistent_dma_mask(pdev, DMA_31BIT_MASK);
at least when IR descriptors are allocated, or
- simply don't use dualbuffer.
This fix implements the latter workaround.

But we keep using dualbuffer on x86-32 which won't give us highmen (and
thus physical addresses outside the 31bit range) in coherent DMA memory
allocations. Right now we could for example also whitelist PPC32, but
DMA mapping implementation details are expected to change there.

Signed-off-by: Stefan Richter <[email protected]>
---
drivers/firewire/fw-ohci.c | 37 ++++++++++++++++++++++++-------------
include/linux/pci_ids.h | 1 +
2 files changed, 25 insertions(+), 13 deletions(-)

Index: linux/drivers/firewire/fw-ohci.c
===================================================================
--- linux.orig/drivers/firewire/fw-ohci.c
+++ linux/drivers/firewire/fw-ohci.c
@@ -171,7 +171,6 @@ struct iso_context {
struct fw_ohci {
struct fw_card card;

- u32 version;
__iomem char *registers;
dma_addr_t self_id_bus;
__le32 *self_id_cpu;
@@ -180,6 +179,8 @@ struct fw_ohci {
int generation;
int request_generation; /* for timestamping incoming requests */
u32 bus_seconds;
+
+ bool use_dualbuffer;
bool old_uninorth;
bool bus_reset_packet_quirk;

@@ -1885,7 +1886,7 @@ ohci_allocate_iso_context(struct fw_card
} else {
mask = &ohci->ir_context_mask;
list = ohci->ir_context_list;
- if (ohci->version >= OHCI_VERSION_1_1)
+ if (ohci->use_dualbuffer)
callback = handle_ir_dualbuffer_packet;
else
callback = handle_ir_packet_per_buffer;
@@ -1949,7 +1950,7 @@ static int ohci_start_iso(struct fw_iso_
} else {
index = ctx - ohci->ir_context_list;
control = IR_CONTEXT_ISOCH_HEADER;
- if (ohci->version >= OHCI_VERSION_1_1)
+ if (ohci->use_dualbuffer)
control |= IR_CONTEXT_DUAL_BUFFER_MODE;
match = (tags << 28) | (sync << 8) | ctx->base.channel;
if (cycle >= 0) {
@@ -2279,7 +2280,7 @@ ohci_queue_iso(struct fw_iso_context *ba
spin_lock_irqsave(&ctx->context.ohci->lock, flags);
if (base->type == FW_ISO_CONTEXT_TRANSMIT)
retval = ohci_queue_iso_transmit(base, packet, buffer, payload);
- else if (ctx->context.ohci->version >= OHCI_VERSION_1_1)
+ else if (ctx->context.ohci->use_dualbuffer)
retval = ohci_queue_iso_receive_dualbuffer(base, packet,
buffer, payload);
else
@@ -2341,7 +2342,7 @@ static int __devinit
pci_probe(struct pci_dev *dev, const struct pci_device_id *ent)
{
struct fw_ohci *ohci;
- u32 bus_options, max_receive, link_speed;
+ u32 bus_options, max_receive, link_speed, version;
u64 guid;
int err;
size_t size;
@@ -2366,12 +2367,6 @@ pci_probe(struct pci_dev *dev, const str
pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
pci_set_drvdata(dev, ohci);

-#if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
- ohci->old_uninorth = dev->vendor == PCI_VENDOR_ID_APPLE &&
- dev->device == PCI_DEVICE_ID_APPLE_UNI_N_FW;
-#endif
- ohci->bus_reset_packet_quirk = dev->vendor == PCI_VENDOR_ID_TI;
-
spin_lock_init(&ohci->lock);

tasklet_init(&ohci->bus_reset_tasklet,
@@ -2390,6 +2385,23 @@ pci_probe(struct pci_dev *dev, const str
goto fail_iomem;
}

+ version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
+ ohci->use_dualbuffer = version >= OHCI_VERSION_1_1;
+
+/* x86-32 currently doesn't use highmem for dma_alloc_coherent */
+#if !defined(CONFIG_X86_32)
+ /* dual-buffer mode is broken with descriptor addresses above 2G */
+ if (dev->vendor == PCI_VENDOR_ID_TI &&
+ dev->device == PCI_DEVICE_ID_TI_TSB43AB22)
+ ohci->use_dualbuffer = false;
+#endif
+
+#if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
+ ohci->old_uninorth = dev->vendor == PCI_VENDOR_ID_APPLE &&
+ dev->device == PCI_DEVICE_ID_APPLE_UNI_N_FW;
+#endif
+ ohci->bus_reset_packet_quirk = dev->vendor == PCI_VENDOR_ID_TI;
+
ar_context_init(&ohci->ar_request_ctx, ohci,
OHCI1394_AsReqRcvContextControlSet);

@@ -2441,9 +2453,8 @@ pci_probe(struct pci_dev *dev, const str
if (err < 0)
goto fail_self_id;

- ohci->version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
fw_notify("Added fw-ohci device %s, OHCI version %x.%x\n",
- dev->dev.bus_id, ohci->version >> 16, ohci->version & 0xff);
+ dev->dev.bus_id, version >> 16, version & 0xff);
return 0;

fail_self_id:
Index: linux/include/linux/pci_ids.h
===================================================================
--- linux.orig/include/linux/pci_ids.h
+++ linux/include/linux/pci_ids.h
@@ -748,6 +748,7 @@
#define PCI_VENDOR_ID_TI 0x104c
#define PCI_DEVICE_ID_TI_TVP4020 0x3d07
#define PCI_DEVICE_ID_TI_4450 0x8011
+#define PCI_DEVICE_ID_TI_TSB43AB22 0x8023
#define PCI_DEVICE_ID_TI_XX21_XX11 0x8031
#define PCI_DEVICE_ID_TI_XX21_XX11_FM 0x8033
#define PCI_DEVICE_ID_TI_XX21_XX11_SD 0x8034

--
Stefan Richter
-=====-==--- -=== =-==-
http://arcgraph.de/sr/


2008-07-22 22:11:38

by Jarod Wilson

[permalink] [raw]
Subject: Re: [PATCH] firewire: fw-ohci: TSB43AB22/A dualbuffer workaround

On Tuesday 22 July 2008 12:41:10 pm Stefan Richter wrote:
> Isochronous reception in dualbuffer is reportedly broken with
> TI TSB43AB22A on x86-64. Descriptor addresses above 2G have been
> determined as the trigger:
> https://bugzilla.redhat.com/show_bug.cgi?id=435550
>
> Two fixes are possible:
> - pci_set_consistent_dma_mask(pdev, DMA_31BIT_MASK);
> at least when IR descriptors are allocated, or
> - simply don't use dualbuffer.
> This fix implements the latter workaround.
>
> But we keep using dualbuffer on x86-32 which won't give us highmen (and
> thus physical addresses outside the 31bit range) in coherent DMA memory
> allocations. Right now we could for example also whitelist PPC32, but
> DMA mapping implementation details are expected to change there.
>
> Signed-off-by: Stefan Richter <[email protected]>

Still hoping we can get some confirmation of a chipset bug or a fix from TI
for this controller, but in the interim, this seems to be the most reasonable
route to go right now.

Signed-off-by: Jarod Wilson <[email protected]>

--
Jarod Wilson
[email protected]

2008-07-22 23:06:37

by Stefan Richter

[permalink] [raw]
Subject: Re: [PATCH] firewire: fw-ohci: TSB43AB22/A dualbuffer workaround

Jarod Wilson wrote:
> Still hoping we can get some confirmation of a chipset bug or a fix from TI
> for this controller,

Well, indeed, a chipset/board bug isn't entirely ruled out yet. But
given that data buffers above 2G don't hurt, only descriptors do, the
controller is definitely the primary suspect here.
--
Stefan Richter
-=====-==--- -=== =-===
http://arcgraph.de/sr/