[PATCH] usb: chipidea: add loop timeout for hw_ep_set_halt()

[PATCH] usb: chipidea: add loop timeout for hw_ep_set_halt()

[Jeaho Hwang]

If ctrl EP priming is failed (very rare case in standard linux),
hw_ep_set_halt goes infinite loop. 50 was enough for zynq7000.

Signed-off-by: Jeaho Hwang <jhhwang@rtst.co.kr>
---
 drivers/usb/chipidea/udc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index d0cd1de1b6c7..92ca0b7e4310 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -210,6 +210,9 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
 	return 0;
 }
 
+/*will it be enough?*/
+#define HW_EP_SET_HALT_COUNT_MAX 100
+
 /**
  * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute
  *                 without interruption)
@@ -222,6 +225,7 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
  */
 static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
 {
+	int count = HW_EP_SET_HALT_COUNT_MAX;
 	if (value != 0 && value != 1)
 		return -EINVAL;
 
@@ -233,9 +237,9 @@ static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
 		/* data toggle - reserved for EP0 but it's in ESS */
 		hw_write(ci, reg, mask_xs|mask_xr,
 			  value ? mask_xs : mask_xr);
-	} while (value != hw_ep_get_halt(ci, num, dir));
+	} while (value != hw_ep_get_halt(ci, num, dir) && --count > 0);
 
-	return 0;
+	return count ? 0 : -EAGAIN;
 }
 
 /**
-- 
2.25.1

Re: [PATCH] usb: chipidea: add loop timeout for hw_ep_set_halt()

[Greg Kroah-Hartman]

On Mon, Aug 09, 2021 at 08:20:48PM +0900, Jeaho Hwang wrote:
> If ctrl EP priming is failed (very rare case in standard linux),
> hw_ep_set_halt goes infinite loop. 50 was enough for zynq7000.
> 
> Signed-off-by: Jeaho Hwang <jhhwang@rtst.co.kr>
> ---
>  drivers/usb/chipidea/udc.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> index d0cd1de1b6c7..92ca0b7e4310 100644
> --- a/drivers/usb/chipidea/udc.c
> +++ b/drivers/usb/chipidea/udc.c
> @@ -210,6 +210,9 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
>  	return 0;
>  }
>  
> +/*will it be enough?*/

Please use ' ' characters in your comments.

And can you answer this, please do not add a question in a comment, be
sure about this.

> +#define HW_EP_SET_HALT_COUNT_MAX 100
> +
>  /**
>   * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute
>   *                 without interruption)
> @@ -222,6 +225,7 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
>   */
>  static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
>  {
> +	int count = HW_EP_SET_HALT_COUNT_MAX;
>  	if (value != 0 && value != 1)

Please use checkpatch.pl when submitting patches :(