[PATCH] usb: host: xhci: make 'usec' parameter of xhci_handshake() *unsigned*

[PATCH] usb: host: xhci: make 'usec' parameter of xhci_handshake() *unsigned*

[Sergey Shtylyov]

The negative timeouts hardly make sense, and the 'usec' parameter of
xhci_handshake() gets assigned to a 'u64' typed local variable in
readl_poll_timeout_atomic() anyways...

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>

---
This patch is against the 'usb-next' branch of Greg KH's 'usb.git' repo.

 drivers/usb/host/xhci.c |    2 +-
 drivers/usb/host/xhci.h |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Index: usb/drivers/usb/host/xhci.c
===================================================================
--- usb.orig/drivers/usb/host/xhci.c
+++ usb/drivers/usb/host/xhci.c
@@ -65,7 +65,7 @@ static bool td_on_ring(struct xhci_td *t
  * handshake done).  There are two failure modes:  "usec" have passed (major
  * hardware flakeout), or the register reads as all-ones (hardware removed).
  */
-int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, int usec)
+int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, unsigned int usec)
 {
 	u32	result;
 	int	ret;
Index: usb/drivers/usb/host/xhci.h
===================================================================
--- usb.orig/drivers/usb/host/xhci.h
+++ usb/drivers/usb/host/xhci.h
@@ -2083,7 +2083,7 @@ void xhci_free_container_ctx(struct xhci
 
 /* xHCI host controller glue */
 typedef void (*xhci_get_quirks_t)(struct device *, struct xhci_hcd *);
-int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, int usec);
+int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, unsigned int usec);
 void xhci_quiesce(struct xhci_hcd *xhci);
 int xhci_halt(struct xhci_hcd *xhci);
 int xhci_start(struct xhci_hcd *xhci);

Re: [PATCH] usb: host: xhci: make 'usec' parameter of xhci_handshake() *unsigned*

[Greg Kroah-Hartman]

On Tue, Feb 15, 2022 at 11:09:21PM +0300, Sergey Shtylyov wrote:
> The negative timeouts hardly make sense, and the 'usec' parameter of
> xhci_handshake() gets assigned to a 'u64' typed local variable in
> readl_poll_timeout_atomic() anyways...

Then why not just make it a u64 instead of a unsigned int?

thanks,

greg k-h

Re: [PATCH] usb: host: xhci: make 'usec' parameter of xhci_handshake() *unsigned*

[Sergey Shtylyov]

On 2/16/22 1:40 PM, Greg Kroah-Hartman wrote:

>> The negative timeouts hardly make sense, and the 'usec' parameter of
>> xhci_handshake() gets assigned to a 'u64' typed local variable in
>> readl_poll_timeout_atomic() anyways...
> 
> Then why not just make it a u64 instead of a unsigned int?

   Because *unsigned int* is enough? :-)

> thanks,
> 
> greg k-h

MBR, Sergey