diff options
Diffstat (limited to 'target/linux/mvebu/patches-5.4/002-PCI-aardvark-Don-t-rely-on-jiffies-while-holding-spi.patch')
| -rw-r--r-- | target/linux/mvebu/patches-5.4/002-PCI-aardvark-Don-t-rely-on-jiffies-while-holding-spi.patch | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-5.4/002-PCI-aardvark-Don-t-rely-on-jiffies-while-holding-spi.patch b/target/linux/mvebu/patches-5.4/002-PCI-aardvark-Don-t-rely-on-jiffies-while-holding-spi.patch new file mode 100644 index 0000000000..db4afd22a2 --- /dev/null +++ b/target/linux/mvebu/patches-5.4/002-PCI-aardvark-Don-t-rely-on-jiffies-while-holding-spi.patch @@ -0,0 +1,54 @@ +From 7fbcb5da811be7d47468417c7795405058abb3da Mon Sep 17 00:00:00 2001 +From: Remi Pommarel <repk@triplefau.lt> +Date: Fri, 27 Sep 2019 10:55:02 +0200 +Subject: [PATCH] PCI: aardvark: Don't rely on jiffies while holding spinlock + +advk_pcie_wait_pio() can be called while holding a spinlock (from +pci_bus_read_config_dword()), then depends on jiffies in order to +timeout while polling on PIO state registers. In the case the PIO +transaction failed, the timeout will never happen and will also cause +the cpu to stall. + +This decrements a variable and wait instead of using jiffies. + +Signed-off-by: Remi Pommarel <repk@triplefau.lt> +Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> +Reviewed-by: Andrew Murray <andrew.murray@arm.com> +Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> +--- + drivers/pci/controller/pci-aardvark.c | 10 +++++----- + 1 file changed, 5 insertions(+), 5 deletions(-) + +--- a/drivers/pci/controller/pci-aardvark.c ++++ b/drivers/pci/controller/pci-aardvark.c +@@ -175,7 +175,8 @@ + (PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \ + PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where)) + +-#define PIO_TIMEOUT_MS 1 ++#define PIO_RETRY_CNT 500 ++#define PIO_RETRY_DELAY 2 /* 2 us*/ + + #define LINK_WAIT_MAX_RETRIES 10 + #define LINK_WAIT_USLEEP_MIN 90000 +@@ -400,17 +401,16 @@ static void advk_pcie_check_pio_status(s + static int advk_pcie_wait_pio(struct advk_pcie *pcie) + { + struct device *dev = &pcie->pdev->dev; +- unsigned long timeout; ++ int i; + +- timeout = jiffies + msecs_to_jiffies(PIO_TIMEOUT_MS); +- +- while (time_before(jiffies, timeout)) { ++ for (i = 0; i < PIO_RETRY_CNT; i++) { + u32 start, isr; + + start = advk_readl(pcie, PIO_START); + isr = advk_readl(pcie, PIO_ISR); + if (!start && isr) + return 0; ++ udelay(PIO_RETRY_DELAY); + } + + dev_err(dev, "config read/write timed out\n"); |