This is a note to let you know that I've just added the patch titled
PCI: aardvark: Don't rely on jiffies while holding spinlock
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-aardvark-don-t-rely-on-jiffies-while-holding-spinlock.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7fbcb5da811be7d47468417c7795405058abb3da Mon Sep 17 00:00:00 2001
From: Remi Pommarel <repk@xxxxxxxxxxxx>
Date: Fri, 27 Sep 2019 10:55:02 +0200
Subject: PCI: aardvark: Don't rely on jiffies while holding spinlock
From: Remi Pommarel <repk@xxxxxxxxxxxx>
commit 7fbcb5da811be7d47468417c7795405058abb3da upstream.
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@xxxxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Reviewed-by: Andrew Murray <andrew.murray@xxxxxxx>
Acked-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -166,7 +166,8 @@
(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
@@ -369,17 +370,16 @@ 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");
Patches currently in stable-queue which might be from repk@xxxxxxxxxxxx are
queue-4.19/pci-aardvark-fix-kernel-panic-during-pio-transfer.patch
queue-4.19/pci-aardvark-don-t-rely-on-jiffies-while-holding-spinlock.patch
