From: Marc Zyngier <marc.zyngier@arm.com>
To: Trent Piepho <tpiepho@impinj.com>
Cc: "gustavo.pimentel@synopsys.com" <gustavo.pimentel@synopsys.com>,
"jingoohan1@gmail.com" <jingoohan1@gmail.com>,
"faiz_abbas@ti.com" <faiz_abbas@ti.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
"helgaas@google.com" <helgaas@google.com>,
"vigneshr@ti.com" <vigneshr@ti.com>,
"Joao.Pinto@synopsys.com" <Joao.Pinto@synopsys.com>
Subject: Re: [PATCH 0/3] PCI: designware: Fixing MSI handling flow
Date: Tue, 27 Nov 2018 07:50:31 +0000 [thread overview]
Message-ID: <86d0qrrmbc.wl-marc.zyngier@arm.com> (raw)
In-Reply-To: <1543247559.18519.13.camel@impinj.com>
On Mon, 26 Nov 2018 15:52:42 +0000,
Trent Piepho <tpiepho@impinj.com> wrote:
>
> On Thu, 2018-11-22 at 12:03 +0000, Gustavo Pimentel wrote:
> >
> > > I just realised (at 1am!) that the first patch is awfully buggy:
> > > - ENABLE and MASK have opposite polarities
> > > - There is nothing initialising the ENABLE and MASK registers
> > >
> > > I've stashed the following fix-up on top of the existing series:
> > >
> > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > index f06e67c60593..0fa9e8fdce66 100644
> > > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > @@ -166,7 +166,7 @@ static void dw_pci_bottom_mask(struct irq_data
> > > *data)
> >
> > (snip)
> >
> > I used your patch and made it more perceptible in my opinion, (basically I
> > transformed the variable irq_mask (previous irq_status) into a mirror of MASK
> > registers, which removed the need for the *NOT* operation and forced the mask
> > operation swap in the callbacks)
>
> This would be the patch that enables all MSI interrupts on driver
> initialization?
>
> I don't think that's a good idea. I was under the impression Marc
> thought that as well. It would be better to enable them when they are
> enabled, via enable and disable methods.
What gain does this bring? Frankly, I see exactly zero advantage of
doing so. It may look cosmetically appealing in the sense that it
makes use of of a register that the IP offers, but for Linux the
advantage is basically null.
Thanks,
M.
--
Jazz is not dead, it just smell funny.
next prev parent reply other threads:[~2018-11-27 7:50 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 22:57 [PATCH 0/3] PCI: designware: Fixing MSI handling flow Marc Zyngier
2018-11-13 22:57 ` [PATCH 1/3] PCI: designware: Use interrupt masking instead of disabling Marc Zyngier
2018-12-03 18:02 ` [1/3] " Niklas Cassel
2018-12-04 9:41 ` [PATCH 1/3] " Gustavo Pimentel
2018-11-13 22:57 ` [PATCH 2/3] PCI: designware: Take lock when ACKing an interrupt Marc Zyngier
2018-11-14 19:08 ` Trent Piepho
2018-12-03 18:02 ` [2/3] " Niklas Cassel
2018-12-04 9:41 ` [PATCH 2/3] " Gustavo Pimentel
2018-11-13 22:57 ` [PATCH 3/3] PCI: designware: Move interrupt acking into the proper callback Marc Zyngier
2018-11-14 19:01 ` Trent Piepho
2018-12-03 18:02 ` [3/3] " Niklas Cassel
2018-12-04 9:41 ` [PATCH 3/3] " Gustavo Pimentel
2018-12-04 10:20 ` Kishon Vijay Abraham I
2018-12-04 13:45 ` Marc Zyngier
2018-12-07 8:12 ` Kishon Vijay Abraham I
2018-12-07 9:45 ` Marc Zyngier
2018-12-07 10:13 ` Kishon Vijay Abraham I
2018-12-11 12:35 ` Lorenzo Pieralisi
2018-12-12 5:54 ` Kishon Vijay Abraham I
2018-11-13 23:16 ` [PATCH 0/3] PCI: designware: Fixing MSI handling flow Gustavo Pimentel
2018-11-14 9:54 ` Marc Zyngier
2018-11-14 19:19 ` Trent Piepho
2018-11-14 22:01 ` Marc Zyngier
2018-11-14 22:25 ` Trent Piepho
2018-11-14 22:44 ` Marc Zyngier
2018-11-14 23:23 ` Trent Piepho
2018-11-19 20:37 ` Trent Piepho
2018-11-22 12:03 ` Gustavo Pimentel
2018-11-22 16:07 ` Gustavo Pimentel
2018-11-22 16:26 ` Lorenzo Pieralisi
2018-11-22 16:38 ` Marc Zyngier
2018-11-22 17:40 ` Gustavo Pimentel
2018-11-26 16:06 ` Trent Piepho
2018-11-27 7:51 ` Marc Zyngier
2018-11-27 17:23 ` Trent Piepho
2018-11-22 17:49 ` Gustavo Pimentel
2018-11-26 15:52 ` Trent Piepho
2018-11-27 7:50 ` Marc Zyngier [this message]
2018-11-27 18:12 ` Trent Piepho
2018-12-07 16:16 ` Gustavo Pimentel
2018-11-14 18:28 ` Trent Piepho
2018-11-14 22:07 ` Marc Zyngier
2018-11-14 22:50 ` Trent Piepho
2018-11-15 15:22 ` Gustavo Pimentel
2018-11-15 18:37 ` Trent Piepho
2018-11-15 19:29 ` Marc Zyngier
2018-11-19 20:14 ` Trent Piepho
2018-11-21 17:24 ` Stanimir Varbanov
2018-12-01 23:50 ` Niklas Cassel
2018-12-02 11:28 ` Stanimir Varbanov
2018-12-03 10:42 ` Lorenzo Pieralisi
2018-12-03 13:09 ` Niklas Cassel
2018-12-03 17:42 ` Lorenzo Pieralisi
2018-12-03 20:31 ` Trent Piepho
2018-12-10 16:17 ` Lorenzo Pieralisi
2018-12-10 16:30 ` Marc Zyngier
2018-12-10 18:15 ` Trent Piepho
2018-12-10 18:31 ` Marc Zyngier
2018-12-10 20:34 ` Trent Piepho
2018-12-12 9:10 ` Gustavo Pimentel
2018-12-12 8:55 ` Gustavo Pimentel
2018-12-11 11:43 ` Lorenzo Pieralisi
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