Re: [PATCH 03/16] ntb: Enable link training for RP mode in the driver probe

From: Bjorn Helgaas
Date: Wed May 20 2015 - 18:20:47 EST


On Wed, May 20, 2015 at 4:46 PM, Hubbe, Allen <Allen.Hubbe@xxxxxxx> wrote:
> From: Bjorn Helgaas [mailto:bhelgaas@xxxxxxxxxx]
>> Please run "git log --oneline drivers/ntb" and make your subject lines
>> consistent. The convention I use in PCI (and what was used in NTB
>> until recently) is
>>
>> - Acronyms and initialisms are capitalized
>> - Subject line is a subsystem prefix ("PCI:", "NTB:", etc.) followed
>> by a complete sentence starting with a capitalized verb, with no
>> period at the end
>
> These are the new subject lines that will be in the v2 of this set.

That helps a lot, thanks.

> NTB: Fix small code format issues in transport
> NTB: Default to CPU memcpy for performance
> NTB: Improve performance with write combining
> NTB: Use NUMA aware memory allocation
> NTB: Use NUMA memory and DMA chan in transport
> NTB: Reset transport QP link stats on down
> NTB: Do not advance transport RX on link down
> NTB: Differentiate transport link down messages
> NTB: Rate limit ntb_qp_link_work
> NTB: Add tool client
> NTB: Add ping pong client

I think these are test cases, not part of the kernel itself. It'd be
nice to know that from the summary. I don't know what the precedent
is for that (if there is one).

> NTB: Intel NTB params for SNB B2B addresses

This sentence no verb :) Not sure what you're doing with those params.

> NTB: Check the DID for workaround error flags

I think there's room to spell out "device ID".

> NTB: Enable link training for RP mode in probe

Is that Root Port?

> NTB: Add NTB hardware abstraction layer
> NTB: Move files in preparation for NTB abstraction

Of course, none of this has anything to do with the patches
themselves, which I don't intend to review because they're out of my
area :)

>>
>> On Wed, May 20, 2015 at 10:41 AM, Allen Hubbe <Allen.Hubbe@xxxxxxx>
>> wrote:
>> > From: Dave Jiang <dave.jiang@xxxxxxxxx>
>> >
>> > Link training for RP should be enabled in the driver probe. We should
>> > not have to wait for transport loaded for this to hapen. Otherwise the
>>
>> s/hapen/happen/
>>
>> > device will not show up on the transparent bridge side.
>> >
>> > Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
>> > ---
>> > drivers/ntb/hw/intel/ntb_hw_intel.c | 10 ++++++++++
>> > 1 file changed, 10 insertions(+)
>> >
>> > diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.c
>> b/drivers/ntb/hw/intel/ntb_hw_intel.c
>> > index 05c4b77..d162f22 100644
>> > --- a/drivers/ntb/hw/intel/ntb_hw_intel.c
>> > +++ b/drivers/ntb/hw/intel/ntb_hw_intel.c
>> > @@ -1333,6 +1333,9 @@ static int snb_poll_link(struct intel_ntb_dev
>> *ndev)
>> >
>> > static int snb_link_is_up(struct intel_ntb_dev *ndev)
>> > {
>> > + if (ndev->ntb.topo == NTB_TOPO_SEC)
>> > + return 1;
>> > +
>> > return NTB_LNK_STA_ACTIVE(ndev->lnk_sta);
>> > }
>> >
>> > @@ -1642,6 +1645,7 @@ static int snb_setup_b2b_mw(struct intel_ntb_dev
>> *ndev,
>> > static int snb_init_ntb(struct intel_ntb_dev *ndev)
>> > {
>> > int rc;
>> > + u32 ntb_ctl;
>> >
>> > if (ndev->bar4_split)
>> > ndev->mw_count = HSX_SPLIT_BAR_MW_COUNT;
>> > @@ -1658,6 +1662,12 @@ static int snb_init_ntb(struct intel_ntb_dev
>> *ndev)
>> > dev_err(ndev_dev(ndev), "NTB Primary config
>> disabled\n");
>> > return -EINVAL;
>> > }
>> > +
>> > + /* enable link to allow secondary side device to
>> appear */
>> > + ntb_ctl = ioread32(ndev->self_mmio + ndev->reg-
>> >ntb_ctl);
>> > + ntb_ctl &= ~NTB_CTL_DISABLE;
>> > + iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg-
>> >ntb_ctl);
>> > +
>> > /* use half the spads for the peer */
>> > ndev->spad_count >>= 1;
>> > ndev->self_reg = &snb_pri_reg;
>> > --
>> > 2.4.0.rc0.43.gcf8a8c6
>> >
>> > --
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