[PATCH 5.15 126/177] usb: cdnsp: Fix lack of spin_lock_irqsave/spin_lock_restore

Greg Kroah-Hartman
2021-12-20T15:00:53Z

From: Pawel Laszczak <pawell@cadence.com>

commit 4c4e162d9cf38528c4f13df09d5755cbc06f6c77 upstream.

Patch puts content of cdnsp_gadget_pullup function inside
spin_lock_irqsave and spin_lock_restore section.
This construction is required here to keep the data consistency,
otherwise some data can be changed e.g. from interrupt context.

Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Reported-by: Ken (Jian) He <jianhe@ambarella.com>
cc: <stable@vger.kernel.org>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Reviewed-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20211214045527.26823-1-pawell@gli-login.cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/cdns3/cdnsp-gadget.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- a/drivers/usb/cdns3/cdnsp-gadget.c
+++ b/drivers/usb/cdns3/cdnsp-gadget.c
@@ -1541,15 +1541,27 @@ static int cdnsp_gadget_pullup(struct us
{
struct cdnsp_device *pdev = gadget_to_cdnsp(gadget);
struct cdns *cdns = dev_get_drvdata(pdev->dev);
+ unsigned long flags;

trace_cdnsp_pullup(is_on);

+ /*
+ * Disable events handling while controller is being
+ * enabled/disabled.
+ */
+ disable_irq(cdns->dev_irq);
+ spin_lock_irqsave(&pdev->lock, flags);
+
if (!is_on) {
cdnsp_reset_device(pdev);
cdns_clear_vbus(cdns);
} else {
cdns_set_vbus(cdns);
}
+
+ spin_unlock_irqrestore(&pdev->lock, flags);
+ enable_irq(cdns->dev_irq);
+
return 0;
}