From: Vignesh R <vigneshr@ti.com>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Jingoo Han <jingoohan1@gmail.com>,
Joao Pinto <Joao.Pinto@synopsys.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Niklas Cassel <niklas.cassel@axis.com>,
<linux-omap@vger.kernel.org>, <linux-pci@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, Vignesh R <vigneshr@ti.com>
Subject: [PATCH 2/3] PCI: dwc: pci-dra7xx: Improve MSI IRQ handling
Date: Fri, 9 Feb 2018 17:34:14 +0530 [thread overview]
Message-ID: <20180209120415.17590-3-vigneshr@ti.com> (raw)
In-Reply-To: <20180209120415.17590-1-vigneshr@ti.com>
We need to ensure that there are no pending MSI IRQ vector set (i.e
PCIE_MSI_INTR0_STATUS reads 0 at least once) before exiting
dra7xx_pcie_msi_irq_handler(). Else, the dra7xx PCIe wrapper will not
register new MSI IRQs even though PCIE_MSI_INTR0_STATUS shows IRQs are
pending. Therefore, keep calling dra7xx_pcie_msi_irq_handler() until it
returns IRQ_NONE, which suggests that PCIE_MSI_INTR0_STATUS is 0.
This fixes a bug, where PCIe wifi cards with 4 DMA queues like Intel
8260 used to throw following error and stall during ping/iperf3 tests.
[ 97.776310] iwlwifi 0000:01:00.0: Queue 9 stuck for 2500 ms.
Signed-off-by: Vignesh R <vigneshr@ti.com>
---
drivers/pci/dwc/pci-dra7xx.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index ed8558d638e5..3420cbf7b60a 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -254,14 +254,31 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
struct dra7xx_pcie *dra7xx = arg;
struct dw_pcie *pci = dra7xx->pci;
struct pcie_port *pp = &pci->pp;
+ int count = 0;
unsigned long reg;
u32 virq, bit;
reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI, reg);
switch (reg) {
case MSI:
- dw_handle_msi_irq(pp);
+ /*
+ * Need to make sure no MSI IRQs are pending before
+ * exiting handler, else the wrapper will not catch new
+ * IRQs. So loop around till dw_handle_msi_irq() returns
+ * IRQ_NONE
+ */
+ while (dw_handle_msi_irq(pp) != IRQ_NONE && count < 1000)
+ count++;
+
+ if (count == 1000) {
+ dev_err(pci->dev, "too much work in msi irq\n");
+ dra7xx_pcie_writel(dra7xx,
+ PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI,
+ reg);
+ return IRQ_HANDLED;
+ }
break;
case INTA:
case INTB:
@@ -275,8 +292,6 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
break;
}
- dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI, reg);
-
return IRQ_HANDLED;
}
--
2.16.1
next prev parent reply other threads:[~2018-02-09 12:04 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-09 12:04 [PATCH 0/3] dra7xx: PCIe IRQ handling rework Vignesh R
2018-02-09 12:04 ` [PATCH 1/3] Revert "PCI: dwc: Clear MSI interrupt status after it is handled, not before" Vignesh R
2018-02-09 13:46 ` Niklas Cassel
2018-02-09 12:04 ` Vignesh R [this message]
2018-02-12 17:58 ` [PATCH 2/3] PCI: dwc: pci-dra7xx: Improve MSI IRQ handling Lorenzo Pieralisi
2018-02-15 4:29 ` Vignesh R
2018-03-01 15:31 ` Vignesh R
2018-03-01 18:18 ` Lorenzo Pieralisi
2018-03-06 15:12 ` Lorenzo Pieralisi
2018-03-09 4:23 ` Vignesh R
2018-03-15 18:10 ` Lorenzo Pieralisi
2018-02-09 12:04 ` [PATCH 3/3] PCI: dwc: pci-dra7xx: Handle legacy and MSI IRQs together Vignesh R
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=20180209120415.17590-3-vigneshr@ti.com \
--to=vigneshr@ti.com \
--cc=Joao.Pinto@synopsys.com \
--cc=bhelgaas@google.com \
--cc=jingoohan1@gmail.com \
--cc=kishon@ti.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=lorenzo.pieralisi@arm.com \
--cc=niklas.cassel@axis.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).