2021-12-14 04:56:23

by Pawel Laszczak

Subject: [PATCH v2] usb: cdnsp: Fix lack of spin_lock_irqsave/spin_lock_restore

From: Pawel Laszczak <[email protected]>

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 <[email protected]>
cc: <[email protected]>
Signed-off-by: Pawel Laszczak <[email protected]>
--

Changelog:
v2:
- added disable_irq/enable_irq as sugester by Peter Chen

drivers/usb/cdns3/cdnsp-gadget.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c
index f6d231760a6a..e07a65b980af 100644
--- a/drivers/usb/cdns3/cdnsp-gadget.c
+++ b/drivers/usb/cdns3/cdnsp-gadget.c
@@ -1544,15 +1544,27 @@ static int cdnsp_gadget_pullup(struct usb_gadget *gadget, int is_on)
{
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;
}

--
2.25.1

2021-12-14 11:37:32

by Peter Chen

Subject: Re: [PATCH v2] usb: cdnsp: Fix lack of spin_lock_irqsave/spin_lock_restore

On 21-12-14 05:55:27, Pawel Laszczak wrote:
> From: Pawel Laszczak <[email protected]>
>
> 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 <[email protected]>
> cc: <[email protected]>
> Signed-off-by: Pawel Laszczak <[email protected]>

Reviewed-by: Peter Chen <[email protected]>

> --
>
> Changelog:
> v2:
> - added disable_irq/enable_irq as sugester by Peter Chen
>
> drivers/usb/cdns3/cdnsp-gadget.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c
> index f6d231760a6a..e07a65b980af 100644
> --- a/drivers/usb/cdns3/cdnsp-gadget.c
> +++ b/drivers/usb/cdns3/cdnsp-gadget.c
> @@ -1544,15 +1544,27 @@ static int cdnsp_gadget_pullup(struct usb_gadget *gadget, int is_on)
> {
> 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;
> }
>
> --
> 2.25.1
>

--

Thanks,
Peter Chen