kirkwood: update patches and configuration (3.10)

[openwrt.git] / target / linux / kirkwood / patches-3.10 / 0019-pci-mvebu-fix-the-emulation-of-the-status-register.patch

diff --git a/target/linux/kirkwood/patches-3.10/0019-pci-mvebu-fix-the-emulation-of-the-status-register.patch b/target/linux/kirkwood/patches-3.10/0019-pci-mvebu-fix-the-emulation-of-the-status-register.patch
new file mode 100644 (file)
index 0000000..7213231
--- /dev/null
+++ b/target/linux/kirkwood/patches-3.10/0019-pci-mvebu-fix-the-emulation-of-the-status-register.patch
@@ -0,0 +1,87 @@
+From 370c8181fd848948aeae371bbc1124dc0dead22b Mon Sep 17 00:00:00 2001
+From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+Date: Thu, 23 May 2013 16:32:53 +0200
+Subject: [PATCH 19/29] pci: mvebu: fix the emulation of the status register
+
+The status register of the PCI configuration space of PCI-to-PCI
+bridges contain some read-only bits, and so write-1-to-clear bits. So,
+the Linux PCI core sometimes writes 0xffff to this status register,
+and in the current PCI-to-PCI bridge emulation code of the Marvell
+driver, we do take all those 1s being written. Even the read-only bits
+are being overwritten.
+
+For now, all the read-only bits should be emulated to have the zero
+value.
+
+The other bits, that are write-1-to-clear bits are used to report
+various kind of errors, and are never set by the emulated bridge, so
+there is no need to support this write-1-to-clear bits mechanism.
+
+As a conclusion, the easiest solution is to simply emulate this status
+register by returning zero when read, and ignore the writes to it.
+
+This has two visible effects:
+
+ * The devsel is no longer 'unknown' in, i.e
+
+   Flags: bus master, 66MHz, user-definable features, ?? devsel, latency 0
+
+   becomes:
+
+   Flags: bus master, 66MHz, user-definable features, fast devsel, latency 0
+
+   in lspci -v.
+
+   This was caused by a value of 11b being read for devsel, which is
+   an invalid value. This 11b value being read was due to a previous
+   write of 0xffff into the status register.
+
+ * The capability list is no longer broken, because we indicate to the
+   Linux PCI core that we don't have a Capabilities Pointer in the PCI
+   configuration space of this bridge. The following message is
+   therefore no longer visible in lspci -v:
+
+   Capabilities: [fc] <chain broken>
+
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+Acked-by: Bjorn Helgaas <bhelgaas@google.com>
+Signed-off-by: Jason Cooper <jason@lakedaemon.net>
+---
+ drivers/pci/host/pci-mvebu.c | 5 +----
+ 1 file changed, 1 insertion(+), 4 deletions(-)
+
+--- a/drivers/pci/host/pci-mvebu.c
++++ b/drivers/pci/host/pci-mvebu.c
+@@ -69,7 +69,6 @@ struct mvebu_sw_pci_bridge {
+       u16 vendor;
+       u16 device;
+       u16 command;
+-      u16 status;
+       u16 class;
+       u8 interface;
+       u8 revision;
+@@ -359,7 +358,6 @@ static void mvebu_sw_pci_bridge_init(str
+ 
+       memset(bridge, 0, sizeof(struct mvebu_sw_pci_bridge));
+ 
+-      bridge->status = PCI_STATUS_CAP_LIST;
+       bridge->class = PCI_CLASS_BRIDGE_PCI;
+       bridge->vendor = PCI_VENDOR_ID_MARVELL;
+       bridge->device = MARVELL_EMULATED_PCI_PCI_BRIDGE_ID;
+@@ -386,7 +384,7 @@ static int mvebu_sw_pci_bridge_read(stru
+               break;
+ 
+       case PCI_COMMAND:
+-              *value = bridge->status << 16 | bridge->command;
++              *value = bridge->command;
+               break;
+ 
+       case PCI_CLASS_REVISION:
+@@ -479,7 +477,6 @@ static int mvebu_sw_pci_bridge_write(str
+       switch (where & ~3) {
+       case PCI_COMMAND:
+               bridge->command = value & 0xffff;
+-              bridge->status = value >> 16;
+               break;
+ 
+       case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1: