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

commit 9cfb31e4c89d200d8ab7cb1e0bb9e6e8d621ca0b upstream.

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 0ca06a3ab71798573a1546c1374077009578f356..f507f055f523c1d786ff6a3f6a019ead538cb83e 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1796,10 +1796,18 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 {
        u32 reg;
 
-       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:
@@ -1848,15 +1856,6 @@ 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;
 }