Revert "xhci: Reset Renesas uPD72020x USB controller for 32-bit DMA issue"

This reverts commit 8466489ef5ba48272ba4fa4ea9f8f403306de4c7.

Now that we can properly reset the uPD72020x without a hard PCI reset, let's get rid of the existing quirks.

Signed-off-by Marc Zyngier <[email protected]>

---
 drivers/usb/host/pci-quirks.c | 20 --------------------
 drivers/usb/host/pci-quirks.h |  1 -
 drivers/usb/host/xhci-pci.c   |  7 -------
 drivers/usb/host/xhci.c       | 21 ++++++++++++---------
 drivers/usb/host/xhci.h       |  2 +-
 5 files changed, 13 insertions(+), 38 deletions(-)

drivers/usb/host/pci-quirks.c +0 -20

index 67ad4bb6919a..3625a5c1a41b 100644
@@ -1268,23 +1268,3 @@ static void quirk_usb_early_handoff(struct pci_dev *pdev)
 }
 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,
 			PCI_CLASS_SERIAL_USB, 8, quirk_usb_early_handoff);
-
-bool usb_xhci_needs_pci_reset(struct pci_dev *pdev)
-{
-	/*
-	 * Our dear uPD72020{1,2} friend only partially resets when
-	 * asked to via the XHCI interface, and may end up doing DMA
-	 * at the wrong addresses, as it keeps the top 32bit of some
-	 * addresses from its previous programming under obscure
-	 * circumstances.
-	 * Give it a good wack at probe time. Unfortunately, this
-	 * needs to happen before we've had a chance to discover any
-	 * quirk, or the system will be in a rather bad state.
-	 */
-	if (pdev->vendor == PCI_VENDOR_ID_RENESAS &&
-	    (pdev->device == 0x0014 || pdev->device == 0x0015))
-		return true;
-
-	return false;
-}
-EXPORT_SYMBOL_GPL(usb_xhci_needs_pci_reset);

drivers/usb/host/pci-quirks.h +0 -1

index 4ca0d9b7e463..63c633077d9e 100644
@@ -16,7 +16,6 @@ void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev);
 void usb_enable_intel_xhci_ports(struct pci_dev *xhci_pdev);
 void usb_disable_xhci_ports(struct pci_dev *xhci_pdev);
 void sb800_prefetch(struct device *dev, int on);
-bool usb_xhci_needs_pci_reset(struct pci_dev *pdev);
 bool usb_amd_pt_check_port(struct device *device, int port);
 #else
 struct pci_dev;

drivers/usb/host/xhci-pci.c +0 -7

index e0a0a12871e2..6372edf339d9 100644
@@ -288,13 +288,6 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
 	driver = (struct hc_driver *)id->driver_data;
 
-	/* For some HW implementation, a XHCI reset is just not enough... */
-	if (usb_xhci_needs_pci_reset(dev)) {
-		dev_info(&dev->dev, "Resetting\n");
-		if (pci_reset_function_locked(dev))
-			dev_warn(&dev->dev, "Reset failed");
-	}
-
 	/* Prevent runtime suspending between USB-2 and USB-3 initialization */
 	pm_runtime_get_noresume(&dev->dev);
 

drivers/usb/host/xhci.c +12 -9

index cd6b48c43007..07272d1ce32a 100644
@@ -4923,16 +4923,19 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
 
 	/*
 	 * Some Renesas controllers get into a weird state if they are
-	 * reset while programmed with 64bit addresses (they will
-	 * preserve the top half of the address in internal, non
-	 * visible registers). You end up with half the address coming
-	 * from the kernel, and the other half coming from the
-	 * firmware. Also, changing the programming leads to extra
-	 * accesses even if the controller is supposed to be
-	 * halted. The controller ends up with a fatal fault, and is
-	 * then ripe for being properly reset.
+	 * reset while programmed with 64bit addresses (they will preserve
+	 * the top half of the address in internal, non visible
+	 * registers). You end up with half the address coming from the
+	 * kernel, and the other half coming from the firmware. Also,
+	 * changing the programming leads to extra accesses even if the
+	 * controller is supposed to be halted. The controller ends up with
+	 * a fatal fault, and is then ripe for being properly reset.
+	 *
+	 * Special care is taken to only apply this if the device is behind
+	 * an iommu. Doing anything when there is no iommu is definitely
+	 * unsafe...
 	 */
-	if (xhci->quirks & XHCI_ZERO_64B_REGS) {
+	if ((xhci->quirks & XHCI_ZERO_64B_REGS) && dev->iommu_group) {
 		u64 val;
 		int i;
 

drivers/usb/host/xhci.h +0 -0

index 5ea0b52b49cc..758864767fd4 100644