• Rafał Miłecki's avatar
    Revert "MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum" · d5ea019f
    Rafał Miłecki authored
    This reverts commit 2a027b47 ("MIPS: BCM47XX: Enable 74K Core
    ExternalSync for PCIe erratum").
    
    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.
    Signed-off-by: default avatarRafał Miłecki <rafal@milecki.pl>
    Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
    Reported-by: default avatarMichael Marley <michael@michaelmarley.com>
    Patchwork: https://patchwork.linux-mips.org/patch/20032/
    URL: https://bugs.openwrt.org/index.php?do=details&task_id=1688
    Cc: Tokunori Ikegami <ikegami@allied-telesis.co.jp>
    Cc: Hauke Mehrtens <hauke@hauke-m.de>
    Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
    Cc: James Hogan <jhogan@kernel.org>
    Cc: Ralf Baechle <ralf@linux-mips.org>
    Cc: linux-mips@linux-mips.org
    d5ea019f
mipsregs.h 90.5 KB