diff options
Diffstat (limited to 'target/linux/brcm47xx/patches-4.4/330-Revert-MIPS-BCM47XX-Enable-74K-Core-ExternalSync-for.patch')
| -rw-r--r-- | target/linux/brcm47xx/patches-4.4/330-Revert-MIPS-BCM47XX-Enable-74K-Core-ExternalSync-for.patch | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/target/linux/brcm47xx/patches-4.4/330-Revert-MIPS-BCM47XX-Enable-74K-Core-ExternalSync-for.patch b/target/linux/brcm47xx/patches-4.4/330-Revert-MIPS-BCM47XX-Enable-74K-Core-ExternalSync-for.patch new file mode 100644 index 0000000..e6cf500 --- /dev/null +++ b/target/linux/brcm47xx/patches-4.4/330-Revert-MIPS-BCM47XX-Enable-74K-Core-ExternalSync-for.patch @@ -0,0 +1,76 @@ +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl> +Date: Fri, 27 Jul 2018 12:39:01 +0200 +Subject: [PATCH] Revert "MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe + erratum" +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +This reverts commit 2a027b47dba6b77ab8c8e47b589ae9bbc5ac6175. + +Enabling ExternalSync caused a regression for BCM4718A1 (used e.g. in +Netgear E3000 and ASUS RT-N16): it simply hangs during PCIe +initialization. It's likely that BCM4717A1 is also affected. + +I didn't notice that earlier as the only BCM47XX devices with PCIe I +own are: +1) BCM4706 with 2 x 14e4:4331 +2) BCM4706 with 14e4:4360 and 14e4:4331 +it appears that BCM4706 is unaffected. + +While BCM5300X-ES300-RDS.pdf seems to document that erratum and its +workarounds (according to quotes provided by Tokunori) it seems not even +Broadcom follows them. + +According to the provided info Broadcom should define CONF7_ES in their +SDK's mipsinc.h and implement workaround in the si_mips_init(). Checking +both didn't reveal such code. It *could* mean Broadcom also had some +problems with the given workaround. + +Reported-by: Michael Marley <michael@michaelmarley.com> +Cc: Tokunori Ikegami <ikegami@allied-telesis.co.jp> +Cc: Paul Burton <paul.burton@mips.com> +Cc: Hauke Mehrtens <hauke@hauke-m.de> +Cc: Chris Packham <chris.packham@alliedtelesis.co.nz> +Cc: stable@vger.kernel.org +Cc: James Hogan <jhogan@kernel.org> +Signed-off-by: Rafał Miłecki <rafal@milecki.pl> +--- + arch/mips/bcm47xx/setup.c | 6 ------ + arch/mips/include/asm/mipsregs.h | 3 --- + 2 files changed, 9 deletions(-) + +--- a/arch/mips/bcm47xx/setup.c ++++ b/arch/mips/bcm47xx/setup.c +@@ -249,12 +249,6 @@ 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 +@@ -605,8 +605,6 @@ + #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) +@@ -2014,7 +2012,6 @@ __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) |