This is a note to let you know that I've just added the patch titled
MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mips-bcm47xx-enable-74k-core-externalsync-for-pcie-erratum.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2a027b47dba6b77ab8c8e47b589ae9bbc5ac6175 Mon Sep 17 00:00:00 2001
From: Tokunori Ikegami <ikegami@xxxxxxxxxxxxxxxxxxxx>
Date: Sun, 3 Jun 2018 23:02:01 +0900
Subject: MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum
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From: Tokunori Ikegami <ikegami@xxxxxxxxxxxxxxxxxxxx>
commit 2a027b47dba6b77ab8c8e47b589ae9bbc5ac6175 upstream.
The erratum and workaround are described by BCM5300X-ES300-RDS.pdf as
below.
R10: PCIe Transactions Periodically Fail
Description: The BCM5300X PCIe does not maintain transaction ordering.
This may cause PCIe transaction failure.
Fix Comment: Add a dummy PCIe configuration read after a PCIe
configuration write to ensure PCIe configuration access
ordering. Set ES bit of CP0 configu7 register to enable
sync function so that the sync instruction is functional.
Resolution: hndpci.c: extpci_write_config()
hndmips.c: si_mips_init()
mipsinc.h CONF7_ES
This is fixed by the CFE MIPS bcmsi chipset driver also for BCM47XX.
Also the dummy PCIe configuration read is already implemented in the
Linux BCMA driver.
Enable ExternalSync in Config7 when CONFIG_BCMA_DRIVER_PCI_HOSTMODE=y
too so that the sync instruction is externalised.
Signed-off-by: Tokunori Ikegami <ikegami@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Paul Burton <paul.burton@xxxxxxxx>
Acked-by: Hauke Mehrtens <hauke@xxxxxxxxxx>
Cc: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
Cc: Rafał Miłecki <zajec5@xxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/19461/
Signed-off-by: James Hogan <jhogan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/mips/bcm47xx/setup.c | 6 ++++++
arch/mips/include/asm/mipsregs.h | 3 +++
2 files changed, 9 insertions(+)
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -249,6 +249,12 @@ static int __init bcm47xx_cpu_fixes(void
*/
if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
cpu_wait = NULL;
+
+ /*
+ * BCM47XX Erratum "R10: PCIe Transactions Periodically Fail"
+ * Enable ExternalSync for sync instruction to take effect
+ */
+ set_c0_config7(MIPS_CONF7_ES);
break;
#endif
}
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -605,6 +605,8 @@
#define MIPS_CONF7_WII (_ULCAST_(1) << 31)
#define MIPS_CONF7_RPS (_ULCAST_(1) << 2)
+/* ExternalSync */
+#define MIPS_CONF7_ES (_ULCAST_(1) << 8)
#define MIPS_CONF7_IAR (_ULCAST_(1) << 10)
#define MIPS_CONF7_AR (_ULCAST_(1) << 16)
@@ -2012,6 +2014,7 @@ __BUILD_SET_C0(status)
__BUILD_SET_C0(cause)
__BUILD_SET_C0(config)
__BUILD_SET_C0(config5)
+__BUILD_SET_C0(config7)
__BUILD_SET_C0(intcontrol)
__BUILD_SET_C0(intctl)
__BUILD_SET_C0(srsmap)
Patches currently in stable-queue which might be from ikegami@xxxxxxxxxxxxxxxxxxxx are
queue-4.4/mtd-cfi_cmdset_0002-change-erase-functions-to-retry-for-error.patch
queue-4.4/mtd-cfi_cmdset_0002-change-write-buffer-to-check-correct-value.patch
queue-4.4/mips-bcm47xx-enable-74k-core-externalsync-for-pcie-erratum.patch
