diff mbox series

usb: xhci: tegra: Add shutdown callback for Tegra XUSB

Message ID 20230718072057.233011-1-haotienh@nvidia.com
State New
Headers
Series usb: xhci: tegra: Add shutdown callback for Tegra XUSB |

Commit Message

HaoTien Hsu July 18, 2023, 7:20 a.m. UTC 
  From: Henry Lin <henryl@nvidia.com>

If memory accesses by the Tegra XUSB controller are translated through
the SMMU (System MMU), the hardware may continue accessing memory even
after the SMMU translations have been disabled during the shutdown
process and this can in turn cause unpredictable crashes.
Fix this by adding a shutdown implementation that ensures the hardware
is turned off during system reboot or shutdown.

Signed-off-by: Henry Lin <henryl@nvidia.com>
Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
---
 drivers/usb/host/xhci-tegra.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

Comments

Thierry Reding July 18, 2023, 7:35 a.m. UTC | #1 
On Tue, Jul 18, 2023 at 03:20:57PM +0800, Haotien Hsu wrote:
> From: Henry Lin <henryl@nvidia.com>
> 
> If memory accesses by the Tegra XUSB controller are translated through
> the SMMU (System MMU), the hardware may continue accessing memory even
> after the SMMU translations have been disabled during the shutdown
> process and this can in turn cause unpredictable crashes.
> Fix this by adding a shutdown implementation that ensures the hardware
> is turned off during system reboot or shutdown.
> 
> Signed-off-by: Henry Lin <henryl@nvidia.com>
> Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
> ---
>  drivers/usb/host/xhci-tegra.c | 28 +++++++++++++++++++++-------
>  1 file changed, 21 insertions(+), 7 deletions(-)

Acked-by: Thierry Reding <treding@nvidia.com>
Thierry Reding July 18, 2023, 7:42 a.m. UTC | #2 
On Tue, Jul 18, 2023 at 03:20:57PM +0800, Haotien Hsu wrote:
> From: Henry Lin <henryl@nvidia.com>
> 
> If memory accesses by the Tegra XUSB controller are translated through
> the SMMU (System MMU), the hardware may continue accessing memory even
> after the SMMU translations have been disabled during the shutdown
> process and this can in turn cause unpredictable crashes.
> Fix this by adding a shutdown implementation that ensures the hardware
> is turned off during system reboot or shutdown.
> 
> Signed-off-by: Henry Lin <henryl@nvidia.com>
> Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
> ---
>  drivers/usb/host/xhci-tegra.c | 28 +++++++++++++++++++++-------
>  1 file changed, 21 insertions(+), 7 deletions(-)

I just noticed that there's a typo in the linux-usb@vger.kernel.org
mailing list address, so you may want to resend this to make sure this
goes to the patch tracker and all.

Thierry
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index a56cc81b9404..6ef2eac9835d 100644
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -1925,6 +1925,15 @@  static int tegra_xusb_probe(struct platform_device *pdev)
 	return err;
 }
 
+static void tegra_xusb_disable(struct tegra_xusb *tegra)
+{
+	tegra_xusb_powergate_partitions(tegra);
+	tegra_xusb_powerdomain_remove(tegra->dev, tegra);
+	tegra_xusb_phy_disable(tegra);
+	tegra_xusb_clk_disable(tegra);
+	regulator_bulk_disable(tegra->soc->num_supplies, tegra->supplies);
+}
+
 static int tegra_xusb_remove(struct platform_device *pdev)
 {
 	struct tegra_xusb *tegra = platform_get_drvdata(pdev);
@@ -1947,18 +1956,22 @@  static int tegra_xusb_remove(struct platform_device *pdev)
 
 	pm_runtime_put(&pdev->dev);
 
-	tegra_xusb_powergate_partitions(tegra);
-
-	tegra_xusb_powerdomain_remove(&pdev->dev, tegra);
-
-	tegra_xusb_phy_disable(tegra);
-	tegra_xusb_clk_disable(tegra);
-	regulator_bulk_disable(tegra->soc->num_supplies, tegra->supplies);
+	tegra_xusb_disable(tegra);
 	tegra_xusb_padctl_put(tegra->padctl);
 
 	return 0;
 }
 
+static void tegra_xusb_shutdown(struct platform_device *pdev)
+{
+	struct tegra_xusb *tegra = platform_get_drvdata(pdev);
+
+	pm_runtime_get_sync(&pdev->dev);
+	disable_irq(tegra->xhci_irq);
+	xhci_shutdown(tegra->hcd);
+	tegra_xusb_disable(tegra);
+}
+
 static bool xhci_hub_ports_suspended(struct xhci_hub *hub)
 {
 	struct device *dev = hub->hcd->self.controller;
@@ -2666,6 +2679,7 @@  MODULE_DEVICE_TABLE(of, tegra_xusb_of_match);
 static struct platform_driver tegra_xusb_driver = {
 	.probe = tegra_xusb_probe,
 	.remove = tegra_xusb_remove,
+	.shutdown = tegra_xusb_shutdown,
 	.driver = {
 		.name = "tegra-xusb",
 		.pm = &tegra_xusb_pm_ops,