6.15-stable review patch. If anyone has any objections, please let me know.
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From: Peng Fan peng.fan@nxp.com
[ Upstream commit f5cb07ec6aabd1bb56adbdeb5f0d70cb524db2cd ]
i.MX95 features several processing domains, Cortex-M7, Cortex-A55 secure, Cortex-A55 non-secure. Each domain could communicate with SCMI firmware with a dedicated MU. But the current NXP SCMI firmware is not a RTOS, all processing logic codes are in interrupt context. So if high priority Cortex-M7 is communicating with SCMI firmware and requires a bit more time to handle the SCMI call, Linux MU TXDB_V2 will be timeout with high possiblity in 1000us(the current value in imx-mailbox.c). Per NXP SCMI firmware design, if timeout, there is no recover logic, so SCMI agents should never timeout and always wait until the check condition met.
Based on the upper reason, enlarge the timeout value to 10ms which is less chance to timeout, and retry if timeout really happends.
Fixes: 5bfe4067d350 ("mailbox: imx: support channel type tx doorbell v2") Signed-off-by: Peng Fan peng.fan@nxp.com Signed-off-by: Jassi Brar jassisinghbrar@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mailbox/imx-mailbox.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c index 6ef8338add0d6..6778afc64a048 100644 --- a/drivers/mailbox/imx-mailbox.c +++ b/drivers/mailbox/imx-mailbox.c @@ -226,7 +226,7 @@ static int imx_mu_generic_tx(struct imx_mu_priv *priv, { u32 *arg = data; u32 val; - int ret; + int ret, count;
switch (cp->type) { case IMX_MU_TYPE_TX: @@ -240,11 +240,20 @@ static int imx_mu_generic_tx(struct imx_mu_priv *priv, case IMX_MU_TYPE_TXDB_V2: imx_mu_write(priv, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), priv->dcfg->xCR[IMX_MU_GCR]); - ret = readl_poll_timeout(priv->base + priv->dcfg->xCR[IMX_MU_GCR], val, - !(val & IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx)), - 0, 1000); - if (ret) - dev_warn_ratelimited(priv->dev, "channel type: %d failure\n", cp->type); + ret = -ETIMEDOUT; + count = 0; + while (ret && (count < 10)) { + ret = + readl_poll_timeout(priv->base + priv->dcfg->xCR[IMX_MU_GCR], val, + !(val & IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx)), + 0, 10000); + + if (ret) { + dev_warn_ratelimited(priv->dev, + "channel type: %d timeout, %d times, retry\n", + cp->type, ++count); + } + } break; default: dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);