[PATCH] firmware: ti_sci: Use system_state to determine polling

From: Nishanth Menon
Date: Mon Jun 19 2023 - 09:13:26 EST


Commit b9e8a7d950ff ("firmware: ti_sci: Switch transport to polled
mode during system suspend") aims to resolve issues with tisci
operations during system suspend operation. However, the system may
enter a no_irq stage in various other usage modes, including power-off
and restart. To determine if polling mode is appropriate, use the
system_state instead.

While at this, drop the unused is_suspending state variable and
related helpers.

Reported-by: Francesco Dolcini <francesco@xxxxxxxxxx>
Reported-by: Wadim Egorov <w.egorov@xxxxxxxxx>
Link: https://lore.kernel.org/all/ZGeHMjlnob2GFyHF@xxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Signed-off-by: Nishanth Menon <nm@xxxxxx>
---
drivers/firmware/ti_sci.c | 35 ++---------------------------------
1 file changed, 2 insertions(+), 33 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 039d92a595ec..dc7906e38f09 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -97,7 +97,6 @@ struct ti_sci_desc {
* @node: list head
* @host_id: Host ID
* @users: Number of users of this instance
- * @is_suspending: Flag set to indicate in suspend path.
*/
struct ti_sci_info {
struct device *dev;
@@ -116,7 +115,6 @@ struct ti_sci_info {
u8 host_id;
/* protected by ti_sci_list_mutex */
int users;
- bool is_suspending;
};

#define cl_to_ti_sci_info(c) container_of(c, struct ti_sci_info, cl)
@@ -418,14 +416,14 @@ static inline int ti_sci_do_xfer(struct ti_sci_info *info,

ret = 0;

- if (!info->is_suspending) {
+ if (system_state <= SYSTEM_RUNNING) {
/* And we wait for the response. */
timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
if (!wait_for_completion_timeout(&xfer->done, timeout))
ret = -ETIMEDOUT;
} else {
/*
- * If we are suspending, we cannot use wait_for_completion_timeout
+ * If we are !running, we cannot use wait_for_completion_timeout
* during noirq phase, so we must manually poll the completion.
*/
ret = read_poll_timeout_atomic(try_wait_for_completion, done_state,
@@ -3281,35 +3279,6 @@ static int tisci_reboot_handler(struct notifier_block *nb, unsigned long mode,
return NOTIFY_BAD;
}

-static void ti_sci_set_is_suspending(struct ti_sci_info *info, bool is_suspending)
-{
- info->is_suspending = is_suspending;
-}
-
-static int ti_sci_suspend(struct device *dev)
-{
- struct ti_sci_info *info = dev_get_drvdata(dev);
- /*
- * We must switch operation to polled mode now as drivers and the genpd
- * layer may make late TI SCI calls to change clock and device states
- * from the noirq phase of suspend.
- */
- ti_sci_set_is_suspending(info, true);
-
- return 0;
-}
-
-static int ti_sci_resume(struct device *dev)
-{
- struct ti_sci_info *info = dev_get_drvdata(dev);
-
- ti_sci_set_is_suspending(info, false);
-
- return 0;
-}
-
-static DEFINE_SIMPLE_DEV_PM_OPS(ti_sci_pm_ops, ti_sci_suspend, ti_sci_resume);
-
/* Description for K2G */
static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = {
.default_host_id = 2,
--
2.40.0