FAILED: patch "[PATCH] net: ipa: request IPA register values be retained" failed to apply to 5.15-stable tree

gregkh
2022-02-04T08:50:41Z

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 34a081761e4e3c35381cbfad609ebae2962fe2f8 Mon Sep 17 00:00:00 2001
From: Alex Elder <elder@linaro.org>
Date: Tue, 1 Feb 2022 09:02:05 -0600
Subject: [PATCH] net: ipa: request IPA register values be retained

In some cases, the IPA hardware needs to request the always-on
subsystem (AOSS) to coordinate with the IPA microcontroller to
retain IPA register values at power collapse. This is done by
issuing a QMP request to the AOSS microcontroller. A similar
request ondoes that request.

We must get and hold the "QMP" handle early, because we might get
back EPROBE_DEFER for that. But the actual request should be sent
while we know the IPA clock is active, and when we know the
microcontroller is operational.

Fixes: 1aac309d3207 ("net: ipa: use autosuspend")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ipa/ipa_power.c b/drivers/net/ipa/ipa_power.c
index b1c6c0fcb654..f2989aac47a6 100644
--- a/drivers/net/ipa/ipa_power.c
+++ b/drivers/net/ipa/ipa_power.c
@@ -11,6 +11,8 @@
#include <linux/pm_runtime.h>
#include <linux/bitops.h>

+#include "linux/soc/qcom/qcom_aoss.h"
+
#include "ipa.h"
#include "ipa_power.h"
#include "ipa_endpoint.h"
@@ -64,6 +66,7 @@ enum ipa_power_flag {
* struct ipa_power - IPA power management information
* @dev: IPA device pointer
* @core: IPA core clock
+ * @qmp: QMP handle for AOSS communication
* @spinlock: Protects modem TX queue enable/disable
* @flags: Boolean state flags
* @interconnect_count: Number of elements in interconnect[]
@@ -72,6 +75,7 @@ enum ipa_power_flag {
struct ipa_power {
struct device *dev;
struct clk *core;
+ struct qmp *qmp;
spinlock_t spinlock; /* used with STOPPED/STARTED power flags */
DECLARE_BITMAP(flags, IPA_POWER_FLAG_COUNT);
u32 interconnect_count;
@@ -382,6 +386,47 @@ void ipa_power_modem_queue_active(struct ipa *ipa)
clear_bit(IPA_POWER_FLAG_STARTED, ipa->power->flags);
}

+static int ipa_power_retention_init(struct ipa_power *power)
+{
+ struct qmp *qmp = qmp_get(power->dev);
+
+ if (IS_ERR(qmp)) {
+ if (PTR_ERR(qmp) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ /* We assume any other error means it's not defined/needed */
+ qmp = NULL;
+ }
+ power->qmp = qmp;
+
+ return 0;
+}
+
+static void ipa_power_retention_exit(struct ipa_power *power)
+{
+ qmp_put(power->qmp);
+ power->qmp = NULL;
+}
+
+/* Control register retention on power collapse */
+void ipa_power_retention(struct ipa *ipa, bool enable)
+{
+ static const char fmt[] = "{ class: bcm, res: ipa_pc, val: %c }";
+ struct ipa_power *power = ipa->power;
+ char buf[36]; /* Exactly enough for fmt[]; size a multiple of 4 */
+ int ret;
+
+ if (!power->qmp)
+ return; /* Not needed on this platform */
+
+ (void)snprintf(buf, sizeof(buf), fmt, enable ? '1' : '0');
+
+ ret = qmp_send(power->qmp, buf, sizeof(buf));
+ if (ret)
+ dev_err(power->dev, "error %d sending QMP %sable request\n",
+ ret, enable ? "en" : "dis");
+}
+
int ipa_power_setup(struct ipa *ipa)
{
int ret;
@@ -438,12 +483,18 @@ ipa_power_init(struct device *dev, const struct ipa_power_data *data)
if (ret)
goto err_kfree;

+ ret = ipa_power_retention_init(power);
+ if (ret)
+ goto err_interconnect_exit;
+
pm_runtime_set_autosuspend_delay(dev, IPA_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(dev);
pm_runtime_enable(dev);

return power;

+err_interconnect_exit:
+ ipa_interconnect_exit(power);
err_kfree:
kfree(power);
err_clk_put:
@@ -460,6 +511,7 @@ void ipa_power_exit(struct ipa_power *power)

pm_runtime_disable(dev);
pm_runtime_dont_use_autosuspend(dev);
+ ipa_power_retention_exit(power);
ipa_interconnect_exit(power);
kfree(power);
clk_put(clk);
diff --git a/drivers/net/ipa/ipa_power.h b/drivers/net/ipa/ipa_power.h
index 2151805d7fbb..6f84f057a209 100644
--- a/drivers/net/ipa/ipa_power.h
+++ b/drivers/net/ipa/ipa_power.h
@@ -40,6 +40,13 @@ void ipa_power_modem_queue_wake(struct ipa *ipa);
*/
void ipa_power_modem_queue_active(struct ipa *ipa);

+/**
+ * ipa_power_retention() - Control register retention on power collapse
+ * @ipa: IPA pointer
+ * @enable: Whether retention should be enabled or disabled
+ */
+void ipa_power_retention(struct ipa *ipa, bool enable);
+
/**
* ipa_power_setup() - Set up IPA power management
* @ipa: IPA pointer
diff --git a/drivers/net/ipa/ipa_uc.c b/drivers/net/ipa/ipa_uc.c
index 856e55a080a7..fe11910518d9 100644
--- a/drivers/net/ipa/ipa_uc.c
+++ b/drivers/net/ipa/ipa_uc.c
@@ -11,6 +11,7 @@

#include "ipa.h"
#include "ipa_uc.h"
+#include "ipa_power.h"

/**
* DOC: The IPA embedded microcontroller
@@ -154,6 +155,7 @@ static void ipa_uc_response_hdlr(struct ipa *ipa, enum ipa_irq_id irq_id)
case IPA_UC_RESPONSE_INIT_COMPLETED:
if (ipa->uc_powered) {
ipa->uc_loaded = true;
+ ipa_power_retention(ipa, true);
pm_runtime_mark_last_busy(dev);
(void)pm_runtime_put_autosuspend(dev);
ipa->uc_powered = false;
@@ -184,6 +186,9 @@ void ipa_uc_deconfig(struct ipa *ipa)

ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_1);
ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_0);
+ if (ipa->uc_loaded)
+ ipa_power_retention(ipa, false);
+
if (!ipa->uc_powered)
return;