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Subject[PATCH] Fix PCIe double initialization bug
pciehp_fix_double_init_bug.patch:

Earlier patches to split out the hardware init for PCIe hotplug
resulted in some one-time initializations being redone on every
resume cycle. Eg. irq/polling initialization.

This patch splits the hardware init into two parts,
and separates the one-time initializations from those
so that they only ever get done once, as intended.

Signed-off-by: Mark Lord <mlord@pobox.com>
---

This patch is for -mm and for Kristen's queue. Not for 2.6.24.

drivers/pci/hotplug/pciehp.h | 2
drivers/pci/hotplug/pciehp_core.c | 2
drivers/pci/hotplug/pciehp_hpc.c | 119 +++++++++++++++-------------
3 files changed, 69 insertions(+), 54 deletions(-)

--- linux/drivers/pci/hotplug/pciehp.h.orig 2007-11-13 23:57:09.000000000 -0500
+++ linux/drivers/pci/hotplug/pciehp.h 2007-11-17 19:10:01.000000000 -0500
@@ -163,7 +163,7 @@
int pcie_init(struct controller *ctrl, struct pcie_device *dev);
int pciehp_enable_slot(struct slot *p_slot);
int pciehp_disable_slot(struct slot *p_slot);
-int pcie_init_hardware(struct controller *ctrl, struct pcie_device *dev);
+int pcie_init_hardware_part2(struct controller *ctrl, struct pcie_device *dev);

static inline struct slot *pciehp_find_slot(struct controller *ctrl, u8 device)
{
--- linux/drivers/pci/hotplug/pciehp_core.c.orig 2007-11-13 23:57:09.000000000 -0500
+++ linux/drivers/pci/hotplug/pciehp_core.c 2007-11-17 19:09:43.000000000 -0500
@@ -521,7 +521,7 @@
u8 status;

/* reinitialize the chipset's event detection logic */
- pcie_init_hardware(ctrl, dev);
+ pcie_init_hardware_part2(ctrl, dev);

t_slot = pciehp_find_slot(ctrl, ctrl->slot_device_offset);

--- linux/drivers/pci/hotplug/pciehp_hpc.c.orig 2007-11-13 23:57:09.000000000 -0500
+++ linux/drivers/pci/hotplug/pciehp_hpc.c 2007-11-17 19:13:49.000000000 -0500
@@ -1067,28 +1067,25 @@
}
#endif

-int pcie_init_hardware(struct controller *ctrl, struct pcie_device *dev)
+static int pcie_init_hardware_part1(struct controller *ctrl,
+ struct pcie_device *dev)
{
int rc;
u16 temp_word;
- u16 intr_enable = 0;
u32 slot_cap;
u16 slot_status;
- struct pci_dev *pdev;
-
- pdev = dev->port;

rc = pciehp_readl(ctrl, SLOTCAP, &slot_cap);
if (rc) {
err("%s: Cannot read SLOTCAP register\n", __FUNCTION__);
- goto abort_free_ctlr;
+ return -1;
}

/* Mask Hot-plug Interrupt Enable */
rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
if (rc) {
err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
- goto abort_free_ctlr;
+ return -1;
}

dbg("%s: SLOTCTRL %x value read %x\n",
@@ -1099,62 +1096,46 @@
rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
if (rc) {
err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__);
- goto abort_free_ctlr;
+ return -1;
}

rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
if (rc) {
err("%s: Cannot read SLOTSTATUS register\n", __FUNCTION__);
- goto abort_free_ctlr;
+ return -1;
}

temp_word = 0x1F; /* Clear all events */
rc = pciehp_writew(ctrl, SLOTSTATUS, temp_word);
if (rc) {
err("%s: Cannot write to SLOTSTATUS register\n", __FUNCTION__);
- goto abort_free_ctlr;
+ return -1;
}
+ return 0;
+}

- if (pciehp_poll_mode) {
- /* Install interrupt polling timer. Start with 10 sec delay */
- init_timer(&ctrl->poll_timer);
- start_int_poll_timer(ctrl, 10);
- } else {
- /* Installs the interrupt handler */
- rc = request_irq(ctrl->pci_dev->irq, pcie_isr, IRQF_SHARED,
- MY_NAME, (void *)ctrl);
- dbg("%s: request_irq %d for hpc%d (returns %d)\n",
- __FUNCTION__, ctrl->pci_dev->irq,
- atomic_read(&pciehp_num_controllers), rc);
- if (rc) {
- err("Can't get irq %d for the hotplug controller\n",
- ctrl->pci_dev->irq);
- goto abort_free_ctlr;
- }
- }
- dbg("pciehp ctrl b:d:f:irq=0x%x:%x:%x:%x\n", pdev->bus->number,
- PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn), dev->irq);
-
- /*
- * If this is the first controller to be initialized,
- * initialize the pciehp work queue
- */
- if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
- pciehp_wq = create_singlethread_workqueue("pciehpd");
- if (!pciehp_wq) {
- rc = -ENOMEM;
- goto abort_free_irq;
- }
- }
+int pcie_init_hardware_part2(struct controller *ctrl, struct pcie_device *dev)
+{
+ int rc;
+ u16 temp_word;
+ u16 intr_enable = 0;
+ u32 slot_cap;
+ u16 slot_status;

rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
if (rc) {
err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
- goto abort_free_irq;
+ goto abort;
}

intr_enable = intr_enable | PRSN_DETECT_ENABLE;

+ rc = pciehp_readl(ctrl, SLOTCAP, &slot_cap);
+ if (rc) {
+ err("%s: Cannot read SLOTCAP register\n", __FUNCTION__);
+ goto abort;
+ }
+
if (ATTN_BUTTN(slot_cap))
intr_enable = intr_enable | ATTN_BUTTN_ENABLE;

@@ -1179,7 +1160,7 @@
rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
if (rc) {
err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__);
- goto abort_free_irq;
+ goto abort;
}
rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
if (rc) {
@@ -1214,14 +1195,7 @@
}
if (rc)
err("%s : disabling interrupts failed\n", __FUNCTION__);
-
-abort_free_irq:
- if (pciehp_poll_mode)
- del_timer_sync(&ctrl->poll_timer);
- else
- free_irq(ctrl->pci_dev->irq, ctrl);
-
-abort_free_ctlr:
+abort:
return -1;
}

@@ -1318,11 +1292,52 @@
ctrl->first_slot = slot_cap >> 19;
ctrl->ctrlcap = slot_cap & 0x0000007f;

- rc = pcie_init_hardware(ctrl, dev);
+ rc = pcie_init_hardware_part1(ctrl, dev);
+ if (rc)
+ goto abort;
+
+ if (pciehp_poll_mode) {
+ /* Install interrupt polling timer. Start with 10 sec delay */
+ init_timer(&ctrl->poll_timer);
+ start_int_poll_timer(ctrl, 10);
+ } else {
+ /* Installs the interrupt handler */
+ rc = request_irq(ctrl->pci_dev->irq, pcie_isr, IRQF_SHARED,
+ MY_NAME, (void *)ctrl);
+ dbg("%s: request_irq %d for hpc%d (returns %d)\n",
+ __FUNCTION__, ctrl->pci_dev->irq,
+ atomic_read(&pciehp_num_controllers), rc);
+ if (rc) {
+ err("Can't get irq %d for the hotplug controller\n",
+ ctrl->pci_dev->irq);
+ goto abort;
+ }
+ }
+ dbg("pciehp ctrl b:d:f:irq=0x%x:%x:%x:%x\n", pdev->bus->number,
+ PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn), dev->irq);
+
+ /*
+ * If this is the first controller to be initialized,
+ * initialize the pciehp work queue
+ */
+ if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
+ pciehp_wq = create_singlethread_workqueue("pciehpd");
+ if (!pciehp_wq) {
+ rc = -ENOMEM;
+ goto abort_free_irq;
+ }
+ }
+
+ rc = pcie_init_hardware_part2(ctrl, dev);
if (rc == 0) {
ctrl->hpc_ops = &pciehp_hpc_ops;
return 0;
}
+abort_free_irq:
+ if (pciehp_poll_mode)
+ del_timer_sync(&ctrl->poll_timer);
+ else
+ free_irq(ctrl->pci_dev->irq, ctrl);
abort:
return -1;
}
-
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