2022-11-24 03:58:24

by xiaowu.ding

Subject: [PATCH] driver:mhuv2:Fix data mode rx startup problem

From: Xiaowu Ding <[email protected]>

When using the arm mhuv2 data transfer mode , sometimes the sender can
not send data anymore ,and sender will blocking because of receiver did not
clear the stat_clear.

The test scene:
A is sender(poll mode) ; B is receiver (interrupt mode)
When A send msg to B ,but B did not have register the mailbox . The B will
miss the message ,and will not clear the stat_clear. So the sender A will
be send blocking status and can not send again anymore.

So the patch just clear the stat_clear within the rx startup function. Just
Drop the last message before receiver will not be ready for receiver .

Signed-off-by: Xiaowu Ding <[email protected]>
---
drivers/mailbox/arm_mhuv2.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/mailbox/arm_mhuv2.c b/drivers/mailbox/arm_mhuv2.c
index a47aef8df52f..7aef458f0b18 100644
--- a/drivers/mailbox/arm_mhuv2.c
+++ b/drivers/mailbox/arm_mhuv2.c
@@ -327,6 +327,14 @@ static int mhuv2_data_transfer_rx_startup(struct mhuv2 *mhu,
{
struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
int i = priv->ch_wn_idx + priv->windows - 1;
+ const int windows = priv->windows;
+ int j, idx;
+
+ /* clear the rx stat_clear */
+ for (j = 0; j < windows; j++) {
+ idx = priv->ch_wn_idx + j;
+ writel_relaxed(0xFFFFFFFF, &mhu->recv->ch_wn[idx].stat_clear);
+ }

/*
* The protocol mandates that all but the last status register must be
--
2.17.1

2022-11-24 05:25:16

by Viresh Kumar

Subject: Re: [PATCH] driver:mhuv2:Fix data mode rx startup problem

On 24-11-22, 11:27, xiaowu.ding wrote:
> From: Xiaowu Ding <[email protected]>
>
> When using the arm mhuv2 data transfer mode , sometimes the sender can
> not send data anymore ,and sender will blocking because of receiver did not
> clear the stat_clear.
>
> The test scene:
> A is sender(poll mode) ; B is receiver (interrupt mode)
> When A send msg to B ,but B did not have register the mailbox . The B will
> miss the message ,and will not clear the stat_clear. So the sender A will
> be send blocking status and can not send again anymore.
>
> So the patch just clear the stat_clear within the rx startup function. Just
> Drop the last message before receiver will not be ready for receiver .
>
> Signed-off-by: Xiaowu Ding <[email protected]>
> ---
> drivers/mailbox/arm_mhuv2.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/mailbox/arm_mhuv2.c b/drivers/mailbox/arm_mhuv2.c
> index a47aef8df52f..7aef458f0b18 100644
> --- a/drivers/mailbox/arm_mhuv2.c
> +++ b/drivers/mailbox/arm_mhuv2.c
> @@ -327,6 +327,14 @@ static int mhuv2_data_transfer_rx_startup(struct mhuv2 *mhu,
> {
> struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
> int i = priv->ch_wn_idx + priv->windows - 1;
> + const int windows = priv->windows;
> + int j, idx;
> +
> + /* clear the rx stat_clear */
> + for (j = 0; j < windows; j++) {
> + idx = priv->ch_wn_idx + j;
> + writel_relaxed(0xFFFFFFFF, &mhu->recv->ch_wn[idx].stat_clear);
> + }

Since this is already done in mhuv2_data_transfer_read_data(), I am not sure why
it is required again.

>
> /*
> * The protocol mandates that all but the last status register must be

--
viresh