Hi James-san, Very sorry for too late to reply to your mail. As reverted the patch already as you know no need to back port. Again very sorry for the problem. Regards, Ikegami > -----Original Message----- > From: James Hogan [mailto:jhogan@xxxxxxxxxx] > Sent: Wednesday, June 06, 2018 12:46 AM > To: IKEGAMI Tokunori > Cc: PACKHAM Chris; Rafał Miłecki; linux-mips@xxxxxxxxxxxxxx > Subject: Re: [PATCH v5 1/1] MIPS: BCM47XX: Enable MIPS32 74K Core > ExternalSync for BCM47XX PCIe erratum > > On Sun, Jun 03, 2018 at 11:02:01PM +0900, Tokunori Ikegami wrote: > > 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 > > I presume this patch is ready to apply now (thanks for the reviews > folks). > > How far back does this need backporting to stable branches? > > It applies easily back to 3.14 I think (commit 3c06b12b046e ("MIPS: > BCM47XX: fix position of cpu_wait disabling")), but you mentioned other > fixes too. Have those been backported too, and if not is there any point > backporting this? > > Thanks > James
