55 lines
1.8 KiB
Diff
55 lines
1.8 KiB
Diff
From 7fbcb5da811be7d47468417c7795405058abb3da Mon Sep 17 00:00:00 2001
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From: Remi Pommarel <repk@triplefau.lt>
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Date: Fri, 27 Sep 2019 10:55:02 +0200
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Subject: [PATCH] PCI: aardvark: Don't rely on jiffies while holding spinlock
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advk_pcie_wait_pio() can be called while holding a spinlock (from
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pci_bus_read_config_dword()), then depends on jiffies in order to
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timeout while polling on PIO state registers. In the case the PIO
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transaction failed, the timeout will never happen and will also cause
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the cpu to stall.
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This decrements a variable and wait instead of using jiffies.
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Signed-off-by: Remi Pommarel <repk@triplefau.lt>
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Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Reviewed-by: Andrew Murray <andrew.murray@arm.com>
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Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
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---
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drivers/pci/controller/pci-aardvark.c | 10 +++++-----
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1 file changed, 5 insertions(+), 5 deletions(-)
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--- a/drivers/pci/controller/pci-aardvark.c
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+++ b/drivers/pci/controller/pci-aardvark.c
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@@ -175,7 +175,8 @@
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(PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \
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PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where))
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-#define PIO_TIMEOUT_MS 1
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+#define PIO_RETRY_CNT 500
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+#define PIO_RETRY_DELAY 2 /* 2 us*/
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#define LINK_WAIT_MAX_RETRIES 10
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#define LINK_WAIT_USLEEP_MIN 90000
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@@ -400,17 +401,16 @@ static void advk_pcie_check_pio_status(s
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static int advk_pcie_wait_pio(struct advk_pcie *pcie)
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{
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struct device *dev = &pcie->pdev->dev;
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- unsigned long timeout;
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+ int i;
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- timeout = jiffies + msecs_to_jiffies(PIO_TIMEOUT_MS);
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-
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- while (time_before(jiffies, timeout)) {
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+ for (i = 0; i < PIO_RETRY_CNT; i++) {
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u32 start, isr;
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start = advk_readl(pcie, PIO_START);
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isr = advk_readl(pcie, PIO_ISR);
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if (!start && isr)
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return 0;
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+ udelay(PIO_RETRY_DELAY);
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}
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dev_err(dev, "config read/write timed out\n");
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