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From: "David Müller" <dave.mueller@gmx.ch>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: linux-pci@vger.kernel.org,
	Richard Zhu <Richard.Zhu@freescale.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached
Date: Thu, 18 Jun 2015 11:10:49 +0200	[thread overview]
Message-ID: <55828B19.5070608@gmx.ch> (raw)
In-Reply-To: <1434616169.3061.5.camel@pengutronix.de>

Lucas Stach wrote:
> I need more explanation for this one. MSI interrupts were certainly
> working fine even with a PCIe switchin between some time back. I think I
> personally tested things with 3.19.
> 
> In the bug report you mention that the MSI_ADDR registers are
> overwritten. Where does the write come from and why is it done?

I don't know. I just instrumented the driver with code to dump the
MSI_ADDR registers and noticed that they were programmed with the
correct value once, but at a later point in time, the value is gone.

Perhaps it's a some kind of partial HW reset of the PCIe host?

I'm working with a rev 1.2 silicon of the i.MX6Q.


WARNING: multiple messages have this Message-ID (diff)
From: dave.mueller@gmx.ch (David Müller)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached
Date: Thu, 18 Jun 2015 11:10:49 +0200	[thread overview]
Message-ID: <55828B19.5070608@gmx.ch> (raw)
In-Reply-To: <1434616169.3061.5.camel@pengutronix.de>

Lucas Stach wrote:
> I need more explanation for this one. MSI interrupts were certainly
> working fine even with a PCIe switchin between some time back. I think I
> personally tested things with 3.19.
> 
> In the bug report you mention that the MSI_ADDR registers are
> overwritten. Where does the write come from and why is it done?

I don't know. I just instrumented the driver with code to dump the
MSI_ADDR registers and noticed that they were programmed with the
correct value once, but at a later point in time, the value is gone.

Perhaps it's a some kind of partial HW reset of the PCIe host?

I'm working with a rev 1.2 silicon of the i.MX6Q.

  reply	other threads:[~2015-06-18  9:10 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-18  7:59 [PATCH] ARM: imx6: Fix non-working MSI interrupts if PCIe switch is attached David Müller
2015-06-18  7:59 ` David Müller
2015-06-18  8:29 ` Lucas Stach
2015-06-18  8:29   ` Lucas Stach
2015-06-18  9:10   ` David Müller [this message]
2015-06-18  9:10     ` David Müller
2015-07-14 18:34 ` Bjorn Helgaas
2015-07-14 18:34   ` Bjorn Helgaas

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