1 From 7fbcb5da811be7d47468417c7795405058abb3da Mon Sep 17 00:00:00 2001
2 From: Remi Pommarel <repk@triplefau.lt>
3 Date: Fri, 27 Sep 2019 10:55:02 +0200
4 Subject: [PATCH] PCI: aardvark: Don't rely on jiffies while holding spinlock
6 advk_pcie_wait_pio() can be called while holding a spinlock (from
7 pci_bus_read_config_dword()), then depends on jiffies in order to
8 timeout while polling on PIO state registers. In the case the PIO
9 transaction failed, the timeout will never happen and will also cause
12 This decrements a variable and wait instead of using jiffies.
14 Signed-off-by: Remi Pommarel <repk@triplefau.lt>
15 Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
16 Reviewed-by: Andrew Murray <andrew.murray@arm.com>
17 Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
19 drivers/pci/controller/pci-aardvark.c | 10 +++++-----
20 1 file changed, 5 insertions(+), 5 deletions(-)
22 --- a/drivers/pci/controller/pci-aardvark.c
23 +++ b/drivers/pci/controller/pci-aardvark.c
25 (PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \
26 PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where))
28 -#define PIO_TIMEOUT_MS 1
29 +#define PIO_RETRY_CNT 500
30 +#define PIO_RETRY_DELAY 2 /* 2 us*/
32 #define LINK_WAIT_MAX_RETRIES 10
33 #define LINK_WAIT_USLEEP_MIN 90000
34 @@ -400,17 +401,16 @@ static void advk_pcie_check_pio_status(s
35 static int advk_pcie_wait_pio(struct advk_pcie *pcie)
37 struct device *dev = &pcie->pdev->dev;
38 - unsigned long timeout;
41 - timeout = jiffies + msecs_to_jiffies(PIO_TIMEOUT_MS);
43 - while (time_before(jiffies, timeout)) {
44 + for (i = 0; i < PIO_RETRY_CNT; i++) {
47 start = advk_readl(pcie, PIO_START);
48 isr = advk_readl(pcie, PIO_ISR);
51 + udelay(PIO_RETRY_DELAY);
54 dev_err(dev, "config read/write timed out\n");