linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Thierry Reding <thierry.reding@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Manikanta Maddireddy <mmaddireddy@nvidia.com>,
	linux-tegra@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pci: tegra: add MSI dependency
Date: Wed, 14 Mar 2018 12:45:15 +0100	[thread overview]
Message-ID: <20180314114515.GC8564@ulmo> (raw)
In-Reply-To: <20180313115218.2246372-1-arnd@arndb.de>

[-- Attachment #1: Type: text/plain, Size: 1323 bytes --]

On Tue, Mar 13, 2018 at 12:52:05PM +0100, Arnd Bergmann wrote:
> Building the tegra PCIe host driver without MSI results in a link
> failure:
> 
> drivers/pci/host/pci-tegra.o:(.data+0x70): undefined reference to `pci_msi_unmask_irq'
> drivers/pci/host/pci-tegra.o:(.data+0x74): undefined reference to `pci_msi_mask_irq'
> 
> This adds the same dependency that everyone else uses.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/pci/host/Kconfig | 1 +
>  1 file changed, 1 insertion(+)

I'm slightly concerned about the dependency. Not that I doubt its
correctness, but because it could mean that PCI_TEGRA is not visible in
the default configuration. The only reason why it is currently visible
is because PCI_MSI is selected by some symbols that also happen to be
enabled. However, what if at some point those symbols are disabled or
removed?

Some architectures make sure that PCI_MSI is enabled by selecting it,
but that's risky, isn't it, because PCI_MSI is user-visible and could
therefore easily lead to conflicts.

Enabling PCI_MSI in the arm64 defconfig would solve the issue and is
good enough for me. I've got a couple of changes to that defconfig in
the Tegra tree for v4.17-rc1, I can add a patch to enable PCI_MSI.

Unless there are any objections.

Thierry

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  parent reply	other threads:[~2018-03-14 11:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-13 11:52 [PATCH] pci: tegra: add MSI dependency Arnd Bergmann
2018-03-14 10:51 ` Lorenzo Pieralisi
2018-03-14 11:45 ` Thierry Reding [this message]
2018-03-14 12:06   ` Arnd Bergmann
2018-03-14 12:13     ` Thierry Reding
2018-03-14 18:34       ` Lorenzo Pieralisi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180314114515.GC8564@ulmo \
    --to=thierry.reding@gmail.com \
    --cc=arnd@arndb.de \
    --cc=bhelgaas@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=mmaddireddy@nvidia.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).