Linux PCI subsystem development
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From: Arnd Bergmann <arnd@arndb.de>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Joao Pinto <Joao.Pinto@synopsys.com>,
	Vineet.Gupta1@synopsys.com, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org,
	CARLOS.PALMINHA@synopsys.com, Alexey.Brodkin@synopsys.com,
	robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com,
	ijc+devicetree@hellion.org.uk, galak@codeaurora.org
Subject: Re: [PATCH v7 2/2] add new platform driver for PCI RC
Date: Wed, 03 Feb 2016 00:27:46 +0100	[thread overview]
Message-ID: <727234287.1RWoeYxhOH@wuerfel> (raw)
In-Reply-To: <20160202231449.GA18009@localhost>

On Tuesday 02 February 2016 17:14:49 Bjorn Helgaas wrote:
> On Tue, Feb 02, 2016 at 09:25:25PM +0100, Arnd Bergmann wrote:
> > On Monday 01 February 2016 18:07:45 Joao Pinto wrote:
> > > +static void synopsys_pcie_establish_link(struct pcie_port *pp)
> > > +{
> > > +   int retries = 0;
> > > +
> > > +   /* check if the link is up or not */
> > > +   for (retries = 0; retries < 10; retries++) {
> > > +           if (dw_pcie_link_up(pp)) {
> > > +                   dev_info(pp->dev, "Link up\n");
> > > +                   return;
> > > +           }
> > > +           mdelay(100);
> > > +   }
> > > +}
> > 
> > That mdelay() needs to be an msleep(). You should never waste
> > a whole second worth of CPU time in a driver.
> 
> There are six other copies of this code, and two of them (exynos and
> spear) have the same problem.

Good point. Maybe move one (correct) copy into the main driver file and
have it called by the other drivers?

IIRC there were some problems in drivers that did a similar
function from the config space accessors where you cannot call
msleep(), but this driver is not one of them.

	Arnd

  reply	other threads:[~2016-02-02 23:28 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-01 18:07 [PATCH v7 0/2] adding PCI support to AXS10x Joao Pinto
2016-02-01 18:07 ` [PATCH v7 1/2] PCI support added to ARC Joao Pinto
2016-02-02 10:48   ` Vineet Gupta
2016-02-01 18:07 ` [PATCH v7 2/2] add new platform driver for PCI RC Joao Pinto
2016-02-02 17:12   ` Bjorn Helgaas
2016-02-02 20:25   ` Arnd Bergmann
2016-02-02 23:14     ` Bjorn Helgaas
2016-02-02 23:27       ` Arnd Bergmann [this message]
2016-02-03 18:05     ` Bjorn Helgaas
2016-02-03 18:12       ` Joao Pinto
2016-02-03 18:38         ` Bjorn Helgaas
2016-02-03 21:01           ` Arnd Bergmann
2016-02-04 11:10             ` Joao Pinto
2016-02-04 13:12               ` Arnd Bergmann
2016-02-04 11:14           ` Joao Pinto
2016-02-04 14:09             ` Joao Pinto
2016-02-04 15:22               ` Arnd Bergmann
2016-02-02 17:14 ` [PATCH v7 0/2] adding PCI support to AXS10x Bjorn Helgaas
2016-02-02 17:17   ` Joao Pinto
2016-02-02 17:24     ` Joao Pinto

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