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From: Bjorn Helgaas <helgaas@kernel.org>
To: "Pali Rohár" <pali@kernel.org>
Cc: "Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Marek Behún" <kabel@kernel.org>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/15] PCI: mvebu: Propagate errors when updating PCI_IO_BASE and PCI_MEM_BASE registers
Date: Fri, 7 Jan 2022 15:55:04 -0600	[thread overview]
Message-ID: <20220107215504.GA406217@bhelgaas> (raw)
In-Reply-To: <20211125124605.25915-9-pali@kernel.org>

On Thu, Nov 25, 2021 at 01:45:58PM +0100, Pali Rohár wrote:
> Properly propagate failure from mvebu_pcie_add_windows() function back to
> the caller mvebu_pci_bridge_emul_base_conf_write() and correctly updates
> PCI_IO_BASE, PCI_MEM_BASE and PCI_IO_BASE_UPPER16 registers on error.
> On error set base value higher than limit value which indicates that
> address range is disabled. 

Does the spec say that if software programs something invalid,
hardware should proactively set the base and limit registers to
disable the window?

I'm not sure I've seen hardware that does this, and it seems ... maybe
a little aggressive.

What happens if software writes the base and limit in the wrong order,
so the window is invalid after the first write but valid after the
second?  That actually sounds like it could be a sensible strategy to
prevent a partially-configured window from being active.

Bjorn

  reply	other threads:[~2022-01-07 21:55 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-25 12:45 [PATCH 00/15] pci: mvebu: Various fixes Pali Rohár
2021-11-25 12:45 ` [PATCH 01/15] PCI: mvebu: Check for valid ports Pali Rohár
2021-11-25 12:45 ` [PATCH 02/15] PCI: mvebu: Check for errors from pci_bridge_emul_init() call Pali Rohár
2021-11-25 12:45 ` [PATCH 03/15] PCI: mvebu: Check that PCI bridge specified in DT has function number zero Pali Rohár
2022-01-07 18:15   ` Bjorn Helgaas
2022-01-07 18:18     ` Pali Rohár
2022-01-07 21:09       ` Bjorn Helgaas
2022-01-07 21:58         ` Pali Rohár
2021-11-25 12:45 ` [PATCH 04/15] PCI: mvebu: Handle invalid size of read config request Pali Rohár
2022-01-07 18:45   ` Bjorn Helgaas
2022-01-07 19:15     ` Russell King (Oracle)
2021-11-25 12:45 ` [PATCH 05/15] PCI: mvebu: Disallow mapping interrupts on emulated bridges Pali Rohár
2022-01-07 21:32   ` Bjorn Helgaas
2022-01-07 22:13     ` Pali Rohár
2022-01-07 23:01       ` Bjorn Helgaas
2022-01-07 23:11         ` Pali Rohár
2021-11-25 12:45 ` [PATCH 06/15] PCI: mvebu: Fix support for bus mastering and PCI_COMMAND on emulated bridge Pali Rohár
2021-11-25 12:45 ` [PATCH 07/15] PCI: mvebu: Do not modify PCI IO type bits in conf_write Pali Rohár
2021-11-25 12:45 ` [PATCH 08/15] PCI: mvebu: Propagate errors when updating PCI_IO_BASE and PCI_MEM_BASE registers Pali Rohár
2022-01-07 21:55   ` Bjorn Helgaas [this message]
2022-01-07 22:28     ` Pali Rohár
2022-01-07 23:16       ` Bjorn Helgaas
2022-01-07 23:46         ` Pali Rohár
2022-01-13  0:19           ` Bjorn Helgaas
2022-01-13 10:35             ` Pali Rohár
2022-01-20 17:50               ` Bjorn Helgaas
2022-01-20 19:08                 ` Pali Rohár
2022-01-20 19:37                   ` Bjorn Helgaas
2021-11-25 12:45 ` [PATCH 09/15] PCI: mvebu: Setup PCIe controller to Root Complex mode Pali Rohár
2021-11-25 12:46 ` [PATCH 10/15] PCI: mvebu: Set PCI Bridge Class Code to PCI Bridge Pali Rohár
2021-11-25 12:46 ` [PATCH 11/15] PCI: mvebu: Fix configuring secondary bus of PCIe Root Port via emulated bridge Pali Rohár
2021-11-25 12:46 ` [PATCH 12/15] PCI: mvebu: Fix support for PCI_BRIDGE_CTL_BUS_RESET on " Pali Rohár
2021-11-25 12:46 ` [PATCH 13/15] PCI: mvebu: Fix support for PCI_EXP_DEVCTL " Pali Rohár
2021-11-25 12:46 ` [PATCH 14/15] PCI: mvebu: Fix support for PCI_EXP_RTSTA " Pali Rohár
2021-11-25 12:46 ` [PATCH 15/15] PCI: mvebu: Fix support for DEVCAP2, DEVCTL2 and LNKCTL2 registers " Pali Rohár
2022-01-04 15:04 ` [PATCH 00/15] pci: mvebu: Various fixes Lorenzo Pieralisi

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