Linux-PCI Archive mirror
 help / color / mirror / Atom feed
From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: linux-pci@vger.kernel.org, "Bjorn Helgaas" <bhelgaas@google.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Maciej W . Rozycki" <macro@orcam.me.uk>,
	"Jonathan Cameron" <Jonathan.Cameron@Huawei.com>,
	"Lukas Wunner" <lukas@wunner.de>,
	"Alexandru Gagniuc" <mr.nuke.me@gmail.com>,
	"Krishna chaitanya chundru" <quic_krichai@quicinc.com>,
	"Srinivas Pandruvada" <srinivas.pandruvada@linux.intel.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: "Daniel Lezcano" <daniel.lezcano@linaro.org>,
	"Amit Kucheria" <amitk@kernel.org>,
	"Zhang Rui" <rui.zhang@intel.com>,
	"Christophe JAILLET" <christophe.jaillet@wanadoo.fr>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH v6 4/8] PCI/quirks: Abstract LBMS seen check into own function
Date: Thu, 16 May 2024 12:32:18 +0300	[thread overview]
Message-ID: <20240516093222.1684-5-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20240516093222.1684-1-ilpo.jarvinen@linux.intel.com>

The speed quirk in pcie_failed_link_retrain() uses the presence of LBMS
bit as one of the triggering conditions effectively monopolizing the
use of that bit. An upcoming change will introduce a PCIe bandwidth
controller which sets up an interrupt to track LBMS. As LBMS will be
cleared by the interrupt handler, the speed quirk will no longer be
able to observe LBMS directly.

As a preparatory step for the change, extract the LBMS seen check into
own function out of pcie_failed_link_retrain().

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/quirks.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2ae06c7b1917..9be942623573 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -33,6 +33,11 @@
 #include <linux/switchtec.h>
 #include "pci.h"
 
+static bool pcie_lbms_seen(struct pci_dev *dev, u16 lnksta)
+{
+	return lnksta & PCI_EXP_LNKSTA_LBMS;
+}
+
 /*
  * Retrain the link of a downstream PCIe port by hand if necessary.
  *
@@ -92,8 +97,7 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
 
 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
 	pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
-	if ((lnksta & (PCI_EXP_LNKSTA_LBMS | PCI_EXP_LNKSTA_DLLLA)) ==
-	    PCI_EXP_LNKSTA_LBMS) {
+	if (!(lnksta & PCI_EXP_LNKSTA_DLLLA) && pcie_lbms_seen(dev, lnksta)) {
 		pci_info(dev, "broken device, retraining non-functional downstream link at 2.5GT/s\n");
 
 		lnkctl2 &= ~PCI_EXP_LNKCTL2_TLS;
-- 
2.39.2


  parent reply	other threads:[~2024-05-16  9:33 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-16  9:32 [PATCH v6 0/8] PCI: Add PCIe bandwidth controller Ilpo Järvinen
2024-05-16  9:32 ` [PATCH v6 1/8] PCI: Protect Link Control 2 Register with RMW locking Ilpo Järvinen
2024-05-16  9:32 ` [PATCH v6 2/8] PCI: Store all PCIe Supported Link Speeds Ilpo Järvinen
2024-05-16  9:32 ` [PATCH v6 3/8] PCI: Refactor pcie_update_link_speed() Ilpo Järvinen
2024-05-16  9:32 ` Ilpo Järvinen [this message]
2024-05-16  9:32 ` [PATCH v6 5/8] PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller Ilpo Järvinen
2024-05-16  9:32 ` [PATCH v6 6/8] PCI/bwctrl: Add API to set PCIe Link Speed Ilpo Järvinen
2024-05-16  9:32 ` [PATCH v6 7/8] thermal: Add PCIe cooling driver Ilpo Järvinen
2024-05-16  9:32 ` [PATCH v6 8/8] selftests/pcie_bwctrl: Create selftests Ilpo Järvinen

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=20240516093222.1684-5-ilpo.jarvinen@linux.intel.com \
    --to=ilpo.jarvinen@linux.intel.com \
    --cc=Jonathan.Cameron@Huawei.com \
    --cc=amitk@kernel.org \
    --cc=bhelgaas@google.com \
    --cc=christophe.jaillet@wanadoo.fr \
    --cc=daniel.lezcano@linaro.org \
    --cc=kw@linux.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=lukas@wunner.de \
    --cc=macro@orcam.me.uk \
    --cc=mr.nuke.me@gmail.com \
    --cc=quic_krichai@quicinc.com \
    --cc=rafael@kernel.org \
    --cc=robh@kernel.org \
    --cc=rui.zhang@intel.com \
    --cc=srinivas.pandruvada@linux.intel.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 read-only IMAP folder(s) and NNTP newsgroup(s).