[Patch v3 3/4] thunderbolt: Store host router reset status in nhi_probe()

[Sanath S]

Currently we do host reset of USB4 v2 in nhi_reset().
In prepration to introduce host rest for USB4 v1, pass on the
reset status to tb_domain_add() to avoid resetting the USB4 v2
routers again.

This boolean helps in resetting only USB4 v1 host routers and
skips resetting v2 routers when reset is introduced for v1 routers.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Sanath S <Sanath.S@xxxxxxx>
---
 drivers/thunderbolt/domain.c |  5 +++--
 drivers/thunderbolt/icm.c    |  2 +-
 drivers/thunderbolt/nhi.c    | 19 +++++++++++++------
 drivers/thunderbolt/tb.c     |  2 +-
 drivers/thunderbolt/tb.h     |  4 ++--
 5 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
index ec7b5f65804e..31f3da4e6a08 100644
--- a/drivers/thunderbolt/domain.c
+++ b/drivers/thunderbolt/domain.c
@@ -423,6 +423,7 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, int timeout_msec, size_t privsize
 /**
  * tb_domain_add() - Add domain to the system
  * @tb: Domain to add
+ * @reset: Issue reset to the host router
  *
  * Starts the domain and adds it to the system. Hotplugging devices will
  * work after this has been returned successfully. In order to remove
@@ -431,7 +432,7 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, int timeout_msec, size_t privsize
  *
  * Return: %0 in case of success and negative errno in case of error
  */
-int tb_domain_add(struct tb *tb)
+int tb_domain_add(struct tb *tb, bool reset)
 {
 	int ret;
 
@@ -460,7 +461,7 @@ int tb_domain_add(struct tb *tb)
 
 	/* Start the domain */
 	if (tb->cm_ops->start) {
-		ret = tb->cm_ops->start(tb);
+		ret = tb->cm_ops->start(tb, reset);
 		if (ret)
 			goto err_domain_del;
 	}
diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index d8b9c734abd3..623aa81a8833 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -2144,7 +2144,7 @@ static int icm_runtime_resume(struct tb *tb)
 	return 0;
 }
 
-static int icm_start(struct tb *tb)
+static int icm_start(struct tb *tb, bool not_used)
 {
 	struct icm *icm = tb_priv(tb);
 	int ret;
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 4b7bec74e89f..1ec6f9c82aef 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -1221,7 +1221,7 @@ static void nhi_check_iommu(struct tb_nhi *nhi)
 		str_enabled_disabled(port_ok));
 }
 
-static void nhi_reset(struct tb_nhi *nhi)
+static bool nhi_reset(struct tb_nhi *nhi)
 {
 	ktime_t timeout;
 	u32 val;
@@ -1229,11 +1229,11 @@ static void nhi_reset(struct tb_nhi *nhi)
 	val = ioread32(nhi->iobase + REG_CAPS);
 	/* Reset only v2 and later routers */
 	if (FIELD_GET(REG_CAPS_VERSION_MASK, val) < REG_CAPS_VERSION_2)
-		return;
+		return false;
 
 	if (!host_reset) {
 		dev_dbg(&nhi->pdev->dev, "skipping host router reset\n");
-		return;
+		return false;
 	}
 
 	iowrite32(REG_RESET_HRR, nhi->iobase + REG_RESET);
@@ -1244,12 +1244,14 @@ static void nhi_reset(struct tb_nhi *nhi)
 		val = ioread32(nhi->iobase + REG_RESET);
 		if (!(val & REG_RESET_HRR)) {
 			dev_warn(&nhi->pdev->dev, "host router reset successful\n");
-			return;
+			return true;
 		}
 		usleep_range(10, 20);
 	} while (ktime_before(ktime_get(), timeout));
 
 	dev_warn(&nhi->pdev->dev, "timeout resetting host router\n");
+
+	return false;
 }
 
 static int nhi_init_msi(struct tb_nhi *nhi)
@@ -1331,6 +1333,7 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	struct device *dev = &pdev->dev;
 	struct tb_nhi *nhi;
 	struct tb *tb;
+	bool reset;
 	int res;
 
 	if (!nhi_imr_valid(pdev))
@@ -1365,7 +1368,11 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	nhi_check_quirks(nhi);
 	nhi_check_iommu(nhi);
 
-	nhi_reset(nhi);
+	/*
+	 * Only USB4 v2 hosts support host reset so if we already did
+	 * that then don't do it again when the domain is initialized.
+	 */
+	reset = nhi_reset(nhi) ? false : host_reset;
 
 	res = nhi_init_msi(nhi);
 	if (res)
@@ -1392,7 +1399,7 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	dev_dbg(dev, "NHI initialized, starting thunderbolt\n");
 
-	res = tb_domain_add(tb);
+	res = tb_domain_add(tb, reset);
 	if (res) {
 		/*
 		 * At this point the RX/TX rings might already have been
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index fd49f86e0353..740bf2ff1fcd 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -2555,7 +2555,7 @@ static int tb_scan_finalize_switch(struct device *dev, void *data)
 	return 0;
 }
 
-static int tb_start(struct tb *tb)
+static int tb_start(struct tb *tb, bool reset)
 {
 	struct tb_cm *tcm = tb_priv(tb);
 	int ret;
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 030d6525cbc9..be419fc87a21 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -481,7 +481,7 @@ struct tb_path {
  */
 struct tb_cm_ops {
 	int (*driver_ready)(struct tb *tb);
-	int (*start)(struct tb *tb);
+	int (*start)(struct tb *tb, bool reset);
 	void (*stop)(struct tb *tb);
 	int (*suspend_noirq)(struct tb *tb);
 	int (*resume_noirq)(struct tb *tb);
@@ -728,7 +728,7 @@ int tb_xdomain_init(void);
 void tb_xdomain_exit(void);
 
 struct tb *tb_domain_alloc(struct tb_nhi *nhi, int timeout_msec, size_t privsize);
-int tb_domain_add(struct tb *tb);
+int tb_domain_add(struct tb *tb, bool reset);
 void tb_domain_remove(struct tb *tb);
 int tb_domain_suspend_noirq(struct tb *tb);
 int tb_domain_resume_noirq(struct tb *tb);
-- 
2.34.1