[PATCH v3 3/8] pciehp: Enable link state change notifications

From: Rajat Jain
Date: Tue Dec 17 2013 - 15:06:05 EST


Enabled the Link state notifications unconditionaly. Enable the
presence detection notification only if attention button is absent.
This was discussed at this thread:
http://marc.info/?t=138611014300001&r=1&w=2

Signed-off-by: Rajat Jain <rajatjain@xxxxxxxxxxx>
Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxx>
---
v3: * created by splitting the patch v2 [2/4]
* Disable presence detect notification, when ATTN BTN is present
v2: (non existent)
v1: (non existent)

drivers/pci/hotplug/pciehp_hpc.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 1e9f814..b45b568 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -723,9 +723,17 @@ int pcie_enable_notification(struct controller *ctrl)
* when it is cleared in the interrupt service routine, and
* next power fault detected interrupt was notified again.
*/
- cmd = PCI_EXP_SLTCTL_PDCE;
+
+ /*
+ * Always enable link events: thus link-up and link-down shall
+ * always be treated as hotplug and unplug respectively. Enable
+ * presence detect only if Attention Button is not present.
+ */
+ cmd = PCI_EXP_SLTCTL_DLLSCE;
if (ATTN_BUTTN(ctrl))
cmd |= PCI_EXP_SLTCTL_ABPE;
+ else
+ cmd |= PCI_EXP_SLTCTL_PDCE;
if (MRL_SENS(ctrl))
cmd |= PCI_EXP_SLTCTL_MRLSCE;
if (!pciehp_poll_mode)
@@ -733,7 +741,8 @@ int pcie_enable_notification(struct controller *ctrl)

mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
- PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
+ PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
+ PCI_EXP_SLTCTL_DLLSCE);

if (pcie_write_cmd(ctrl, cmd, mask)) {
ctrl_err(ctrl, "Cannot enable software notification\n");
--
1.7.9.5

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