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pciehp: Fix wrong slot control register access
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Current pciehp implementaion clears hotplug events without waiting for
command completion. Because of this, events might not be cleared properly.
To prevent this problem, we must use pciehp_write_cmd() to write to
Slot Control register.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by:  Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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Kenji Kaneshige authored and Jesse Barnes committed Apr 25, 2008
1 parent 2d32a9a commit c27fb88
Showing 1 changed file with 38 additions and 112 deletions.
150 changes: 38 additions & 112 deletions drivers/pci/hotplug/pciehp_hpc.c
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Original file line number Diff line number Diff line change
@@ -242,13 +242,12 @@ static inline int pcie_wait_cmd(struct controller *ctrl)

/**
* pcie_write_cmd - Issue controller command
* @slot: slot to which the command is issued
* @ctrl: controller to which the command is issued
* @cmd: command value written to slot control register
* @mask: bitmask of slot control register to be modified
*/
static int pcie_write_cmd(struct slot *slot, u16 cmd, u16 mask)
static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
{
struct controller *ctrl = slot->ctrl;
int retval = 0;
u16 slot_status;
u16 slot_ctrl;
@@ -468,7 +467,7 @@ static int hpc_toggle_emi(struct slot *slot)
cmd_mask = cmd_mask | HP_INTR_ENABLE;
}

rc = pcie_write_cmd(slot, slot_cmd, cmd_mask);
rc = pcie_write_cmd(slot->ctrl, slot_cmd, cmd_mask);
slot->last_emi_toggle = get_seconds();

return rc;
@@ -500,7 +499,7 @@ static int hpc_set_attention_status(struct slot *slot, u8 value)
cmd_mask = cmd_mask | HP_INTR_ENABLE;
}

rc = pcie_write_cmd(slot, slot_cmd, cmd_mask);
rc = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
dbg("%s: SLOTCTRL %x write cmd %x\n",
__func__, ctrl->cap_base + SLOTCTRL, slot_cmd);

@@ -520,7 +519,7 @@ static void hpc_set_green_led_on(struct slot *slot)
cmd_mask = cmd_mask | HP_INTR_ENABLE;
}

pcie_write_cmd(slot, slot_cmd, cmd_mask);
pcie_write_cmd(ctrl, slot_cmd, cmd_mask);

dbg("%s: SLOTCTRL %x write cmd %x\n",
__func__, ctrl->cap_base + SLOTCTRL, slot_cmd);
@@ -539,7 +538,7 @@ static void hpc_set_green_led_off(struct slot *slot)
cmd_mask = cmd_mask | HP_INTR_ENABLE;
}

pcie_write_cmd(slot, slot_cmd, cmd_mask);
pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
dbg("%s: SLOTCTRL %x write cmd %x\n",
__func__, ctrl->cap_base + SLOTCTRL, slot_cmd);
}
@@ -557,7 +556,7 @@ static void hpc_set_green_led_blink(struct slot *slot)
cmd_mask = cmd_mask | HP_INTR_ENABLE;
}

pcie_write_cmd(slot, slot_cmd, cmd_mask);
pcie_write_cmd(ctrl, slot_cmd, cmd_mask);

dbg("%s: SLOTCTRL %x write cmd %x\n",
__func__, ctrl->cap_base + SLOTCTRL, slot_cmd);
@@ -620,7 +619,7 @@ static int hpc_power_on_slot(struct slot * slot)
HP_INTR_ENABLE;
}

retval = pcie_write_cmd(slot, slot_cmd, cmd_mask);
retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);

if (retval) {
err("%s: Write %x command failed!\n", __func__, slot_cmd);
@@ -704,7 +703,7 @@ static int hpc_power_off_slot(struct slot * slot)
HP_INTR_ENABLE;
}

retval = pcie_write_cmd(slot, slot_cmd, cmd_mask);
retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
if (retval) {
err("%s: Write command failed!\n", __func__);
retval = -1;
@@ -1036,130 +1035,57 @@ int pciehp_acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev)
static int pcie_init_hardware_part1(struct controller *ctrl,
struct pcie_device *dev)
{
int rc;
u16 temp_word;
u32 slot_cap;
u16 slot_status;

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

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

dbg("%s: SLOTCTRL %x value read %x\n",
__func__, ctrl->cap_base + SLOTCTRL, temp_word);
temp_word = (temp_word & ~HP_INTR_ENABLE & ~CMD_CMPL_INTR_ENABLE) |
0x00;

rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
if (rc) {
err("%s: Cannot write to SLOTCTRL register\n", __func__);
return -1;
}

rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
if (rc) {
err("%s: Cannot read SLOTSTATUS register\n", __func__);
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", __func__);
if (pcie_write_cmd(ctrl, 0, HP_INTR_ENABLE | CMD_CMPL_INTR_ENABLE)) {
err("%s: Cannot mask hotplug interrupt enable\n", __func__);
return -1;
}
return 0;
}

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", __func__);
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", __func__);
goto abort;
}

if (ATTN_BUTTN(slot_cap))
intr_enable = intr_enable | ATTN_BUTTN_ENABLE;

if (POWER_CTRL(slot_cap))
intr_enable = intr_enable | PWR_FAULT_DETECT_ENABLE;

if (MRL_SENS(slot_cap))
intr_enable = intr_enable | MRL_DETECT_ENABLE;

temp_word = (temp_word & ~intr_enable) | intr_enable;

if (pciehp_poll_mode) {
temp_word = (temp_word & ~HP_INTR_ENABLE) | 0x0;
} else {
temp_word = (temp_word & ~HP_INTR_ENABLE) | HP_INTR_ENABLE;
}
u16 cmd, mask;

/*
* Unmask Hot-plug Interrupt Enable for the interrupt
* notification mechanism case.
* We need to clear all events before enabling hotplug interrupt
* notification mechanism in order for hotplug controler to
* generate interrupts.
*/
rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
if (rc) {
err("%s: Cannot write to SLOTCTRL register\n", __func__);
goto abort;
}
rc = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
if (rc) {
err("%s: Cannot read SLOTSTATUS register\n", __func__);
goto abort_disable_intr;
if (pciehp_writew(ctrl, SLOTSTATUS, 0x1f)) {
err("%s: Cannot write to SLOTSTATUS register\n", __FUNCTION__);
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", __func__);
goto abort_disable_intr;
cmd = PRSN_DETECT_ENABLE;
if (ATTN_BUTTN(ctrl->ctrlcap))
cmd |= ATTN_BUTTN_ENABLE;
if (POWER_CTRL(ctrl->ctrlcap))
cmd |= PWR_FAULT_DETECT_ENABLE;
if (MRL_SENS(ctrl->ctrlcap))
cmd |= MRL_DETECT_ENABLE;
if (!pciehp_poll_mode)
cmd |= HP_INTR_ENABLE;

mask = PRSN_DETECT_ENABLE | ATTN_BUTTN_ENABLE |
PWR_FAULT_DETECT_ENABLE | MRL_DETECT_ENABLE | HP_INTR_ENABLE;

if (pcie_write_cmd(ctrl, cmd, mask)) {
err("%s: Cannot enable software notification\n", __func__);
goto abort;
}

if (pciehp_force) {
if (pciehp_force)
dbg("Bypassing BIOS check for pciehp use on %s\n",
pci_name(ctrl->pci_dev));
} else {
rc = pciehp_get_hp_hw_control_from_firmware(ctrl->pci_dev);
if (rc)
goto abort_disable_intr;
}
else if (pciehp_get_hp_hw_control_from_firmware(ctrl->pci_dev))
goto abort_disable_intr;

return 0;

/* We end up here for the many possible ways to fail this API. */
abort_disable_intr:
rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
if (!rc) {
temp_word &= ~(intr_enable | HP_INTR_ENABLE);
rc = pciehp_writew(ctrl, SLOTCTRL, temp_word);
}
if (rc)
if (pcie_write_cmd(ctrl, 0, HP_INTR_ENABLE))
err("%s : disabling interrupts failed\n", __func__);
abort:
return -1;

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