usb: dwc3: fix fault at system suspend if device was already runtime suspended

If the device was already runtime suspended then during system suspend
we cannot access the device registers else it will crash.

Also we cannot access any registers after dwc3_core_exit() on some
platforms so move the dwc3_enable_susphy() call to the top.

Cc: stable@vger.kernel.org # v5.15+
Reported-by: William McVicker <willmcvicker@google.com>
Closes: https://lore.kernel.org/all/ZyVfcUuPq56R2m1Y@google.com
Fixes: 705e3ce37bcc ("usb: dwc3: core: Fix system suspend on TI AM62 platforms")
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Tested-by: Will McVicker <willmcvicker@google.com>
Link: https://lore.kernel.org/r/20241104-am62-lpm-usb-fix-v1-1-e93df73a4f0d@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 427e5660f87c248572fbe7f4424e9613ae5909c3..98114c2827c09889e63b340450804f7a6d0907d2 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2342,10 +2342,18 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
        u32 reg;
        int i;
 
-       dwc->susphy_state = (dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) &
-                           DWC3_GUSB2PHYCFG_SUSPHY) ||
-                           (dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0)) &
-                           DWC3_GUSB3PIPECTL_SUSPHY);
+       if (!pm_runtime_suspended(dwc->dev) && !PMSG_IS_AUTO(msg)) {
+               dwc->susphy_state = (dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) &
+                                   DWC3_GUSB2PHYCFG_SUSPHY) ||
+                                   (dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0)) &
+                                   DWC3_GUSB3PIPECTL_SUSPHY);
+               /*
+                * TI AM62 platform requires SUSPHY to be
+                * enabled for system suspend to work.
+                */
+               if (!dwc->susphy_state)
+                       dwc3_enable_susphy(dwc, true);
+       }
 
        switch (dwc->current_dr_role) {
        case DWC3_GCTL_PRTCAP_DEVICE:
@@ -2398,15 +2406,6 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
                break;
        }
 
-       if (!PMSG_IS_AUTO(msg)) {
-               /*
-                * TI AM62 platform requires SUSPHY to be
-                * enabled for system suspend to work.
-                */
-               if (!dwc->susphy_state)
-                       dwc3_enable_susphy(dwc, true);
-       }
-
        return 0;
 }