Re: [BUG] Bisected Problem with LSI PCI FC Adapter

Yinghai Lu
2014-09-11T19:26:57Z

[-- Attachment #1: Type: text/plain, Size: 2956 bytes --]

On Thu, Sep 11, 2014 at 10:30 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> [+cc linux-pci]
>
>
> On Thu, Sep 11, 2014 at 7:43 AM, Dirk Gouders <dirk@gouders.net> wrote:
>> Andreas Noever <andreas.noever@gmail.com> writes:
>>
>>> On Wed, Sep 3, 2014 at 2:47 PM, Dirk Gouders <dirk@gouders.net> wrote:
>>>> Andreas Noever <andreas.noever@gmail.com> writes:
>>>>
>>>>> On Wed, Sep 3, 2014 at 12:57 PM, Dirk Gouders <dirk@gouders.net> wrote:
>>>>>> On a Tyan VX50 (B4985) I ran into problems when updating the kernel: the
>>>>>> PCI FC Adapter is no longer recognized.
>>>>>
>>>>> Can you provide the output of lspci -vvv and the output of dmesg from
>>>>> a working boot? Which card is the one that is not recognized?
>>>>
>>>> Sure, the card that disappeared is:
>>>>
>>>> 0a:00.0 Fibre Channel: LSI Logic / Symbios Logic FC949ES Fibre Channel Adapter (rev 02)
>>>
>>> As far as I can tell the following is happening:
>>> The root bus resource window (advertised by the bios?) is to small:
>>> pci_bus 0000:00: root bus resource [bus 00-07]
>>> Previously we didn't really care. There is a resource conflict but we
>>> ignored it:
>>> pci_bus 0000:0a: busn_res: can not insert [bus 0a] under [bus 00-07]
>>> (conflicts with (null) [bus 00-07])
>>> With the patch we mark the bridge as broken and reassign the bus to 06:
>>> pci 0000:00:0e.0: bridge configuration invalid ([bus 0a-0a]), reconfiguring
>>> pci 0000:00:0e.0: PCI bridge to [bus 06-07]
>>> pci 0000:00:0e.0: bridge window [io 0x3000-0x3fff]
>>> pci 0000:00:0e.0: bridge window [mem 0xd4200000-0xd42fffff]
>>> pci_bus 0000:06: busn_res: [bus 06-07] end is updated to 06

> Thanks for following up on this. It had fallen off my radar, so I
> opened https://bugzilla.kernel.org/show_bug.cgi?id=84281 to make sure
> I don't forget again. Please continue the debug discussion here in
> email.

Two problems here:
1. This is amd two node systems. amd_bus.c tell us bus [00, 7f] is from
first socket, but _OSC says only [0,7] is from first socket.

So solution (1):
According to Linus's principle, we should always trust HW than firmware,
so should we just adjust bus range from _OSC before we use it?

2. After moving, LSI FC card from bus 0a to bus 07, the LSI refuse to respond.

During my testing with pci busn allocation patchset, I found that if changing
LSI Erie card to different bus, it will refuse to responding. Only
thing that will
make the LSI card again, is resetting the pcie link. This should be LSI firmware
bug.

Dirk, please check if you can apply attached patches to use

echo 1 > /sys/bus/pci/devices/0000\:00\0e.0/link_disable
echo 0 > /sys/bus/pci/devices/0000\:00\0e.0/link_disable

to reset the link.

Solution (2)
To workaround the problem, we could reset the pcie link after change bus num
in the pcie bridges ?

Soultion (3)
Or we just revert the offending 1820ffdccb9b4398 (PCI: Make sure
bus number resources stay within their parents bounds) ?

Thanks

Yinghai

[-- Attachment #2: move_pcie_link_disable_1.patch --]
[-- Type: text/x-patch, Size: 2628 bytes --]

Subject: [PATCH] PCI: Add generic pcie_link_disable

Remove not needed return value checking that Linus pointed out before.

Will use it from /sys/.../pcie/link_disable

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
drivers/pci/Makefile | 2 +-
drivers/pci/pcie-link.c | 42 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 2 ++
3 files changed, 45 insertions(+), 1 deletion(-)

Index: linux-2.6/drivers/pci/pcie-link.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/pci/pcie-link.c
@@ -0,0 +1,42 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+
+int pcie_link_disable_get(struct pci_dev *dev)
+{
+ u16 lnk_ctrl;
+ if (!pci_is_pcie(dev))
+ return 0;
+
+ pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctrl);
+
+ return !!(lnk_ctrl & PCI_EXP_LNKCTL_LD);
+}
+
+void pcie_link_disable_set(struct pci_dev *dev, int bit)
+{
+ u16 lnk_ctrl, old_lnk_ctrl;
+
+ if (!pci_is_pcie(dev))
+ return;
+
+ pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctrl);
+ old_lnk_ctrl = lnk_ctrl;
+
+ if (!bit)
+ lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
+ else
+ lnk_ctrl |= PCI_EXP_LNKCTL_LD;
+
+ if (old_lnk_ctrl == lnk_ctrl)
+ return;
+
+ pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctrl);
+
+ dev_printk(KERN_DEBUG, &dev->dev, "%s: lnk_ctrl = %x\n", __func__,
+ lnk_ctrl);
+}
+EXPORT_SYMBOL(pcie_link_disable_set);
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -842,6 +842,8 @@ struct pci_bus *pci_scan_root_bus(struct
struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
int busnr);
void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
+void pcie_link_disable_set(struct pci_dev *dev, int bit);
+int pcie_link_disable_get(struct pci_dev *dev);
struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
const char *name,
struct hotplug_slot *hotplug);
Index: linux-2.6/drivers/pci/Makefile
===================================================================
--- linux-2.6.orig/drivers/pci/Makefile
+++ linux-2.6/drivers/pci/Makefile
@@ -4,7 +4,7 @@

obj-y += access.o bus.o probe.o host-bridge.o remove.o pci.o \
pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
- irq.o vpd.o setup-bus.o vc.o
+ irq.o vpd.o setup-bus.o pcie-link.o vc.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_SYSFS) += slot.o

[-- Attachment #3: move_pcie_link_disable_2.patch --]
[-- Type: text/x-patch, Size: 1947 bytes --]

Subject: [PATCH] PCI, pciehp: Use generic pcie_link_disable

Also remove old version with not needed return check.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
drivers/pci/hotplug/pciehp_hpc.c | 30 +++---------------------------
1 file changed, 3 insertions(+), 27 deletions(-)

Index: linux-2.6/drivers/pci/hotplug/pciehp_hpc.c
===================================================================
--- linux-2.6.orig/drivers/pci/hotplug/pciehp_hpc.c
+++ linux-2.6/drivers/pci/hotplug/pciehp_hpc.c
@@ -305,28 +305,6 @@ int pciehp_check_link_status(struct cont
return 0;
}

-static int __pciehp_link_set(struct controller *ctrl, bool enable)
-{
- struct pci_dev *pdev = ctrl_dev(ctrl);
- u16 lnk_ctrl;
-
- pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl);
-
- if (enable)
- lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
- else
- lnk_ctrl |= PCI_EXP_LNKCTL_LD;
-
- pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl);
- ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
- return 0;
-}
-
-static int pciehp_link_enable(struct controller *ctrl)
-{
- return __pciehp_link_set(ctrl, true);
-}
-
void pciehp_get_attention_status(struct slot *slot, u8 *status)
{
struct controller *ctrl = slot->ctrl;
@@ -473,7 +451,6 @@ int pciehp_power_on_slot(struct slot * s
struct controller *ctrl = slot->ctrl;
struct pci_dev *pdev = ctrl_dev(ctrl);
u16 slot_status;
- int retval;

/* Clear sticky power-fault bit from previous power failures */
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
@@ -487,11 +464,10 @@ int pciehp_power_on_slot(struct slot * s
pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
PCI_EXP_SLTCTL_PWR_ON);

- retval = pciehp_link_enable(ctrl);
- if (retval)
- ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
+ /* Enable the link */
+ pcie_link_disable_set(ctrl->pcie->port, 0);

- return retval;
+ return 0;
}

void pciehp_power_off_slot(struct slot * slot)

[-- Attachment #4: pci_express_link.patch --]
[-- Type: text/x-patch, Size: 2574 bytes --]

Subject: [PATCH] PCI, sysfs: Add pcie attrs for pcie device under pci dev dir.

Will put link_disable and link_retrain

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
drivers/pci/Makefile | 2 +-
drivers/pci/pci-sysfs.c | 1 +
drivers/pci/pci.h | 1 +
drivers/pci/pcie-sysfs.c | 23 +++++++++++++++++++++++
4 files changed, 26 insertions(+), 1 deletion(-)

Index: linux-2.6/drivers/pci/pci-sysfs.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-sysfs.c
+++ linux-2.6/drivers/pci/pci-sysfs.c
@@ -1608,6 +1608,7 @@ static struct attribute_group pci_dev_br
static const struct attribute_group *pci_dev_attr_groups[] = {
&pci_dev_attr_group,
&pci_dev_bridge_attr_group,
+ &pci_dev_pcie_attr_group,
&pci_dev_hp_attr_group,
#ifdef CONFIG_PCI_IOV
&sriov_dev_attr_group,
Index: linux-2.6/drivers/pci/pcie-sysfs.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/pci/pcie-sysfs.c
@@ -0,0 +1,23 @@
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+static struct attribute *pci_dev_pcie_dev_attrs[] = {
+ NULL,
+};
+
+static umode_t pci_dev_pcie_attrs_are_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ if (!pci_is_pcie(pdev))
+ return 0;
+
+ return a->mode;
+}
+
+struct attribute_group pci_dev_pcie_attr_group = {
+ .is_visible = pci_dev_pcie_attrs_are_visible,
+ .attrs = pci_dev_pcie_dev_attrs,
+};
Index: linux-2.6/drivers/pci/pci.h
===================================================================
--- linux-2.6.orig/drivers/pci/pci.h
+++ linux-2.6/drivers/pci/pci.h
@@ -152,6 +152,7 @@ static inline int pci_no_d1d2(struct pci
extern const struct attribute_group *pci_dev_groups[];
extern const struct attribute_group *pcibus_groups[];
extern struct device_type pci_dev_type;
+extern struct attribute_group pci_dev_pcie_attr_group;
extern const struct attribute_group *pci_bus_groups[];

Index: linux-2.6/drivers/pci/Makefile
===================================================================
--- linux-2.6.orig/drivers/pci/Makefile
+++ linux-2.6/drivers/pci/Makefile
@@ -4,7 +4,7 @@

obj-y += access.o bus.o probe.o host-bridge.o remove.o pci.o \
pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
- irq.o vpd.o setup-bus.o pcie-link.o vc.o
+ irq.o vpd.o setup-bus.o pcie-link.o pcie-sysfs.o vc.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_SYSFS) += slot.o

[-- Attachment #5: pci_express_link_disable.patch --]
[-- Type: text/x-patch, Size: 1930 bytes --]

Subject: [PATCH] PCI: Add link_disable in /sysfs for pcie device

Found PCIe cards from one vendor, will not respond to scan from bridge,
if we change bus number setting in bridge device.

Have to do link disable/enable on the pcie root port.

So try to expose link disable bit of pcie link control register. We can use
echo 1 > /sys/..../link_disable
echo 0 > /sys/..../link_disable
to bring the pcie device back to respond to scan.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
drivers/pci/pcie-sysfs.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

Index: linux-2.6/drivers/pci/pcie-sysfs.c
===================================================================
--- linux-2.6.orig/drivers/pci/pcie-sysfs.c
+++ linux-2.6/drivers/pci/pcie-sysfs.c
@@ -1,7 +1,35 @@
#include <linux/kernel.h>
#include <linux/pci.h>

+static ssize_t
+pcie_link_disable_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return sprintf(buf, "%u\n", pcie_link_disable_get(pdev));
+}
+static ssize_t
+pcie_link_disable_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ unsigned long val;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ pcie_link_disable_set(pdev, val);
+
+ return count;
+}
+
+static struct device_attribute pcie_link_disable_attr =
+ __ATTR(pcie_link_disable, 0644,
+ pcie_link_disable_show, pcie_link_disable_store);
+
static struct attribute *pci_dev_pcie_dev_attrs[] = {
+ &pcie_link_disable_attr.attr,
NULL,
};

@@ -14,6 +42,11 @@ static umode_t pci_dev_pcie_attrs_are_vi
if (!pci_is_pcie(pdev))
return 0;

+ if (a == &pcie_link_disable_attr.attr)
+ if ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
+ (pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM))
+ return 0;
+
return a->mode;
}