From: Pali Rohár pali@kernel.org
stable inclusion from linux-4.19.207 commit 19d29895971c1ba4d1a31577221aa2bb1931586b
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commit 02bcec3ea5591720114f586960490b04b093a09e upstream.
Measurements in different conditions showed that aardvark hardware PIO response can take up to 1.44s. Increase wait timeout from 1ms to 1.5s to ensure that we do not miss responses from hardware. After 1.44s hardware returns errors (e.g. Completer abort).
The previous two patches fixed checking for PIO status, so now we can use it to also catch errors which are reported by hardware after 1.44s.
After applying this patch, kernel can detect and print PIO errors to dmesg:
[ 6.879999] advk-pcie d0070000.pcie: Non-posted PIO Response Status: CA, 0xe00 @ 0x100004 [ 6.896436] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100004 [ 6.913049] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100010 [ 6.929663] advk-pcie d0070000.pcie: Non-posted PIO Response Status: CA, 0xe00 @ 0x100010 [ 6.953558] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100014 [ 6.970170] advk-pcie d0070000.pcie: Non-posted PIO Response Status: CA, 0xe00 @ 0x100014 [ 6.994328] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100004
Without this patch kernel prints only a generic error to dmesg:
[ 5.246847] advk-pcie d0070000.pcie: config read/write timed out
Link: https://lore.kernel.org/r/20210722144041.12661-3-pali@kernel.org Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Reviewed-by: Marek Behún kabel@kernel.org Cc: stable@vger.kernel.org # 7fbcb5da811b ("PCI: aardvark: Don't rely on jiffies while holding spinlock") Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/pci/controller/pci-aardvark.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 74aa9da85aa26..5e3fb894e5683 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -166,7 +166,7 @@ (PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \ PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where))
-#define PIO_RETRY_CNT 500 +#define PIO_RETRY_CNT 750000 /* 1.5 s */ #define PIO_RETRY_DELAY 2 /* 2 us*/
#define LINK_WAIT_MAX_RETRIES 10