From: Leonard Crestez <leonard.crestez@nxp.com>
To: "stefan@agner.ch" <stefan@agner.ch>,
"l.stach@pengutronix.de" <l.stach@pengutronix.de>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>
Cc: Richard Zhu <hongxing.zhu@nxp.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"jingoohan1@gmail.com" <jingoohan1@gmail.com>,
"gustavo.pimentel@synopsys.com" <gustavo.pimentel@synopsys.com>,
"andrew.smirnov@gmail.com" <andrew.smirnov@gmail.com>,
"tpiepho@impinj.com" <tpiepho@impinj.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"bhelgaas@google.com" <bhelgaas@google.com>
Subject: Re: [PATCH v3 2/2] PCI: imx6: limit DBI register length
Date: Tue, 20 Nov 2018 18:19:08 +0000 [thread overview]
Message-ID: <581b9548043d5276f6685f534386180fd0673a9a.camel@nxp.com> (raw)
In-Reply-To: <20181120165626.26424-2-stefan@agner.ch>
On Tue, 2018-11-20 at 17:56 +0100, Stefan Agner wrote:
> Define the length of the DBI registers. This makes sure that
> the kernel does not access registers beyond that point, avoiding
> the following abort on a i.MX 6Quad:
> # cat
> /sys/devices/soc0/soc/1ffc000.pcie/pci0000\:00/0000\:00\:00.0/config
> [ 100.021433] Unhandled fault: imprecise external abort (0x1406)
> at 0xb6ea7000
> ...
> [ 100.056423] PC is at dw_pcie_read+0x50/0x84
> [ 100.060790] LR is at dw_pcie_rd_own_conf+0x44/0x48
I don't know exactly where this limitation comes from, I can indeed
reproduce a stack dump when dumping pci config from /sys/
Unfortunately this seems to block access to registers used for
functionality like interrupts. For example dw_handle_msi_irq does:
dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS +
(i * MSI_REG_CTRL_BLOCK_SIZE),
4, &val);
where PCI_MSI_INTR0_STATUS is 0x830. There are more accesses like this.
Testing on 6dl-sabreauto (dts change required) with an ath9k pcie card
with your series I sometimes get "irq 295: nobody cared" on boot. Maybe
I'm missing something?
--
Regards,
Leonard
next prev parent reply other threads:[~2018-11-20 18:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-20 16:56 [PATCH v3 1/2] PCI: imx6: introduce drvdata Stefan Agner
2018-11-20 16:56 ` [PATCH v3 2/2] PCI: imx6: limit DBI register length Stefan Agner
2018-11-20 18:19 ` Leonard Crestez [this message]
2018-11-20 19:13 ` Trent Piepho
2018-11-20 20:42 ` Stefan Agner
2018-11-20 21:28 ` Trent Piepho
2018-11-21 13:47 ` Leonard Crestez
2018-11-21 14:17 ` Lorenzo Pieralisi
2018-11-28 12:19 ` Stefan Agner
2018-11-28 17:36 ` Stefan Agner
2018-11-28 17:50 ` Lucas Stach
2018-11-28 17:56 ` Stefan Agner
2018-11-28 18:01 ` Leonard Crestez
2018-11-26 10:16 ` Leonard Crestez
2018-11-26 16:34 ` Trent Piepho
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