thunderbolt: Do not touch the hardware if the NHI is gone on resume

On PCs the NHI host controller is only present when there is a device
connected. When the last device is disconnected the host controller will
dissappear shortly (within 10s). Now if that happens when we are
suspended we should not try to touch the hardware anymore, so add a flag
for this and check it before we re-enable rings.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index c358c074f9253d131f377c10f8e39aef3b4fca30..14311535661d276f28cc43e1c76e1272fc71dfc5 100644 (file)
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -403,6 +403,8 @@ void ring_start(struct tb_ring *ring)
 {
        mutex_lock(&ring->nhi->lock);
        mutex_lock(&ring->lock);
+       if (ring->nhi->going_away)
+               goto err;
        if (ring->running) {
                dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
                goto err;
@@ -449,6 +451,8 @@ void ring_stop(struct tb_ring *ring)
        mutex_lock(&ring->lock);
        dev_info(&ring->nhi->pdev->dev, "stopping %s %d\n",
                 RING_TYPE(ring), ring->hop);
+       if (ring->nhi->going_away)
+               goto err;
        if (!ring->running) {
                dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n",
                         RING_TYPE(ring), ring->hop);
@@ -653,6 +657,14 @@ static int nhi_resume_noirq(struct device *dev)
        struct pci_dev *pdev = to_pci_dev(dev);
        struct tb *tb = pci_get_drvdata(pdev);
 
+       /*
+        * Check that the device is still there. It may be that the user
+        * unplugged last device which causes the host controller to go
+        * away on PCs.
+        */
+       if (!pci_device_is_present(pdev))
+               tb->nhi->going_away = true;
+
        return tb_domain_resume_noirq(tb);
 }
 

diff --git a/drivers/thunderbolt/nhi.h b/drivers/thunderbolt/nhi.h
index 446ff6dac91d661388879bba6eff06496cb31669..953864ae0ab3dcaf979f997cee96e9ad09bbe8af 100644 (file)
--- a/drivers/thunderbolt/nhi.h
+++ b/drivers/thunderbolt/nhi.h
@@ -20,6 +20,8 @@
  * @tx_rings: All Tx rings available on this host controller
  * @rx_rings: All Rx rings available on this host controller
  * @msix_ida: Used to allocate MSI-X vectors for rings
+ * @going_away: The host controller device is about to disappear so when
+ *             this flag is set, avoid touching the hardware anymore.
  * @interrupt_work: Work scheduled to handle ring interrupt when no
  *                 MSI-X is used.
  * @hop_count: Number of rings (end point hops) supported by NHI.
@@ -31,6 +33,7 @@ struct tb_nhi {
        struct tb_ring **tx_rings;
        struct tb_ring **rx_rings;
        struct ida msix_ida;
+       bool going_away;
        struct work_struct interrupt_work;
        u32 hop_count;
 };