On Wed, Jun 03, 2026 at 03:05:08PM +0200, Sebastian Andrzej Siewior wrote:
>Split the mailbox irq handling into a primary handler (imx_mu_isr()) and
>a threaded handler (imx_mu_isr_th()). The primary handler masks the
>interrupt event so the threaded handler can run without raising the
>interrupt again. The threaded handler can invoke the actuall callback in
>preemtible context.
>
>As a first step, prepare the logic and move TX handling part.
>
>Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
>---
> drivers/mailbox/imx-mailbox.c | 33 ++++++++++++++++++++++++++++++---
> 1 file changed, 30 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
>index d1de07cc0ed62..006aa76b74b62 100644
>--- a/drivers/mailbox/imx-mailbox.c
>+++ b/drivers/mailbox/imx-mailbox.c
>@@ -81,6 +81,7 @@ struct imx_mu_con_priv {
> struct mbox_chan *chan;
> struct work_struct txdb_work;
> bool shutdown;
>+ bool pending;
> };
>
> struct imx_mu_priv {
>@@ -539,11 +540,35 @@ static void imx_mu_txdb_work(struct work_struct *t)
> mbox_chan_txdone(cp->chan, 0);
> }
>
>+static irqreturn_t imx_mu_isr_th(int irq, void *p)
>+{
>+ struct mbox_chan *chan = p;
>+ struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
>+ struct imx_mu_con_priv *cp = chan->con_priv;
>+
>+ if (!cp->pending)
>+ return IRQ_NONE;
Is there a chance that cp->pending could be false here?
Regards
Peng
>+
>+ switch (cp->type) {
>+ case IMX_MU_TYPE_TX:
>+ cp->pending = false;
>+ mbox_chan_txdone(chan, 0);
>+ break;
>+
>+ default:
>+ dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
>+ cp->type);
>+ return IRQ_NONE;
>+ }
>+ return IRQ_HANDLED;
>+}
>+
> static irqreturn_t imx_mu_isr(int irq, void *p)
> {
> struct mbox_chan *chan = p;
> struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
> struct imx_mu_con_priv *cp = chan->con_priv;
>+ irqreturn_t ret = IRQ_HANDLED;
> u32 val, ctrl;
>
> switch (cp->type) {
>@@ -579,7 +604,8 @@ static irqreturn_t imx_mu_isr(int irq, void *p)
> if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
> (cp->type == IMX_MU_TYPE_TX)) {
> imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0,
> IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
>- mbox_chan_txdone(chan, 0);
>+ cp->pending = true;
>+ ret = IRQ_WAKE_THREAD;
> } else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
> (cp->type == IMX_MU_TYPE_RX)) {
> priv->dcfg->rx(priv, cp);
>@@ -594,7 +620,7 @@ static irqreturn_t imx_mu_isr(int irq, void *p)
> if (priv->suspend)
> pm_system_wakeup();
>
>- return IRQ_HANDLED;
>+ return ret;
> }
>
> static int imx_mu_send_data(struct mbox_chan *chan, void *data)
>@@ -629,7 +655,8 @@ static int imx_mu_startup(struct mbox_chan *chan)
> if (!(priv->dcfg->type & IMX_MU_V2_IRQ))
> irq_flag |= IRQF_SHARED;
>
>- ret = request_irq(priv->irq[cp->type], imx_mu_isr, irq_flag,
>cp->irq_desc, chan);
>+ ret = request_threaded_irq(priv->irq[cp->type], imx_mu_isr,
>imx_mu_isr_th,
>+ irq_flag, cp->irq_desc, chan);
> if (ret) {
> dev_err(priv->dev, "Unable to acquire IRQ %d\n",
> priv->irq[cp->type]);
> return ret;
>
>--
>2.53.0
>
