LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Amey Narkhede <ameynarkhede03@gmail.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: alex.williamson@redhat.com,
	Raphael Norwitz <raphael.norwitz@nutanix.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	kw@linux.com, Shanker Donthineni <sdonthineni@nvidia.com>,
	Sinan Kaya <okaya@kernel.org>, Len Brown <lenb@kernel.org>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>
Subject: Re: [PATCH v10 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism
Date: Wed, 28 Jul 2021 23:29:50 +0530	[thread overview]
Message-ID: <20210728175950.q75qcrfas5mcjych@archlinux> (raw)
In-Reply-To: <20210727232808.GA754831@bjorn-Precision-5520>

On 21/07/27 06:28PM, Bjorn Helgaas wrote:
> On Fri, Jul 09, 2021 at 06:08:09PM +0530, Amey Narkhede wrote:
> > Add reset_method sysfs attribute to enable user to query and set user
> > preferred device reset methods and their ordering.
> >
> > Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> > ---
> >  Documentation/ABI/testing/sysfs-bus-pci |  19 +++++
> >  drivers/pci/pci-sysfs.c                 | 103 ++++++++++++++++++++++++
> >  2 files changed, 122 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> > index ef00fada2..43f4e33c7 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-pci
> > +++ b/Documentation/ABI/testing/sysfs-bus-pci
> > @@ -121,6 +121,25 @@ Description:
> >  		child buses, and re-discover devices removed earlier
> >  		from this part of the device tree.
> >
> > +What:		/sys/bus/pci/devices/.../reset_method
> > +Date:		March 2021
> > +Contact:	Amey Narkhede <ameynarkhede03@gmail.com>
> > +Description:
> > +		Some devices allow an individual function to be reset
> > +		without affecting other functions in the same slot.
> > +
> > +		For devices that have this support, a file named
> > +		reset_method will be present in sysfs. Initially reading
> > +		this file will give names of the device supported reset
> > +		methods and their ordering. After write, this file will
> > +		give names and ordering of currently enabled reset methods.
> > +		Writing the name or comma separated list of names of any of
> > +		the device supported reset methods to this file will set
> > +		the reset methods and their ordering to be used when
> > +		resetting the device. Writing empty string to this file
> > +		will disable ability to reset the device and writing
> > +		"default" will return to the original value.
> > +
> >  What:		/sys/bus/pci/devices/.../reset
> >  Date:		July 2009
> >  Contact:	Michael S. Tsirkin <mst@redhat.com>
>
[...]

> > +		int i;
> > +
> > +		if (sysfs_streq(name, ""))
> > +			continue;
> > +
> > +		name = strim(name);
> > +
> > +		for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
> > +			if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
> > +			    !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
> > +				reset_methods[n++] = i;
>
> Can we build this directly in pdev->reset_methods[] so we don't need
> the memcpy() below?
>
This is to avoid writing partial values directly to dev->reset_methods.
So for example if user writes flr,unsupported_value then
dev->reset_methods should not be modified even though flr is valid reset
method in this example to avoid partial writes. Either operation(in this
case writing supported reset methods to reset_method attr) succeeds
completely or it fails othewise.

Thanks,
Amey

[...]

  parent reply	other threads:[~2021-07-28 17:59 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-09 12:38 [PATCH v10 0/8] Expose and manage PCI device reset Amey Narkhede
2021-07-09 12:38 ` [PATCH v10 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
2021-07-12 22:07   ` Alex Williamson
2021-07-27 22:12   ` Bjorn Helgaas
2021-07-28 18:54     ` Shanker R Donthineni
2021-07-28 20:23       ` Bjorn Helgaas
2021-07-28 21:58         ` Shanker R Donthineni
2021-07-28 22:04           ` Shanker R Donthineni
2021-07-28 22:16           ` Bjorn Helgaas
2021-07-09 12:38 ` [PATCH v10 2/8] PCI: Add new array for keeping track of ordering of " Amey Narkhede
2021-07-27 22:59   ` Bjorn Helgaas
2021-07-28 17:45     ` Amey Narkhede
2021-07-28 17:59       ` Bjorn Helgaas
2021-07-28 18:17         ` Shanker R Donthineni
2021-07-28 18:08       ` Shanker R Donthineni
2021-07-28 18:31     ` Shanker R Donthineni
2021-07-28 20:25       ` Bjorn Helgaas
2021-07-28 22:01         ` Shanker R Donthineni
2021-07-09 12:38 ` [PATCH v10 3/8] PCI: Remove reset_fn field from pci_dev Amey Narkhede
2021-07-09 12:38 ` [PATCH v10 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
2021-07-27 23:28   ` Bjorn Helgaas
2021-07-28  1:27     ` Krzysztof Wilczyński
2021-07-28 15:36       ` Bjorn Helgaas
2021-07-28 17:59     ` Amey Narkhede [this message]
2021-07-28 18:13       ` Bjorn Helgaas
2021-07-28 18:58         ` Amey Narkhede
2021-07-28 20:18           ` Bjorn Helgaas
2021-07-31 19:15     ` Amey Narkhede
2021-07-28 17:09   ` Bjorn Helgaas
2021-07-09 12:38 ` [PATCH v10 5/8] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
2021-07-12 22:29   ` Alex Williamson
2021-07-09 12:38 ` [PATCH v10 6/8] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
2021-07-12 23:09   ` Alex Williamson
2021-07-27 23:30   ` Bjorn Helgaas
2021-07-27 23:50     ` Shanker R Donthineni
2021-07-09 12:38 ` [PATCH v10 7/8] PCI: Add support for ACPI _RST reset method Amey Narkhede
2021-07-12 23:09   ` Alex Williamson
2021-07-13  0:51     ` Shanker R Donthineni
2021-07-14 22:56       ` Alex Williamson
2021-07-09 12:38 ` [PATCH v10 8/8] PCI: Change the type of probe argument in reset functions Amey Narkhede
2021-07-12 22:24   ` Alex Williamson
2021-07-27 22:22   ` Bjorn Helgaas
2021-07-28 17:35     ` Amey Narkhede
2021-07-28 17:55       ` Bjorn Helgaas
2021-07-09 12:46 ` [PATCH v10 0/8] Expose and manage PCI device reset Amey Narkhede

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=20210728175950.q75qcrfas5mcjych@archlinux \
    --to=ameynarkhede03@gmail.com \
    --cc=alex.williamson@redhat.com \
    --cc=helgaas@kernel.org \
    --cc=kw@linux.com \
    --cc=lenb@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=okaya@kernel.org \
    --cc=raphael.norwitz@nutanix.com \
    --cc=rjw@rjwysocki.net \
    --cc=sdonthineni@nvidia.com \
    --subject='Re: [PATCH v10 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism' \
    /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

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).