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From:   Bagas Sanjaya <bagasdotme@gmail.com>
To:     Linux Networking <netdev@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Regressions <regressions@lists.linux.dev>
Cc:     Loic Poulain <loic.poulain@linaro.org>,
        Sergey Ryazanov <ryazanov.s.a@gmail.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
        Martin <mwolf@adiumentum.com>
Subject: [PATCH net] Revert "net: wwan: iosm: enable runtime pm support for 7560"
Date:   Tue, 17 Oct 2023 15:08:12 +0700
Message-ID: <20231017080812.117892-1-bagasdotme@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Runtime power management support breaks Intel LTE modem where dmesg dump
showes timeout errors:

```
[   72.027442] iosm 0000:01:00.0: msg timeout
[   72.531638] iosm 0000:01:00.0: msg timeout
[   73.035414] iosm 0000:01:00.0: msg timeout
[   73.540359] iosm 0000:01:00.0: msg timeout
```

Furthermore, when shutting down with `poweroff` and modem attached, the
system rebooted instead of powering down as expected. The modem works
again only after power cycling.

Revert runtime power management support for IOSM driver as introduced by
commit e4f5073d53be6c ("net: wwan: iosm: enable runtime pm support for
7560").

Fixes: e4f5073d53be ("net: wwan: iosm: enable runtime pm support for 7560")
Reported-by: Martin <mwolf@adiumentum.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217996
Link: https://lore.kernel.org/r/267abf02-4b60-4a2e-92cd-709e3da6f7d3@gmail.com/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---

 Compile-tested only.

 I explicitly do not Cc: the culprit author (M Chetan Kumar) as he can't
 be contacted (see his MAINTAINERS entry removal [1] for why).

 [1]: https://lore.kernel.org/netdev/20231013014010.18338-2-bagasdotme@gmail.com/

 drivers/net/wwan/iosm/iosm_ipc_imem.c  | 17 -----------------
 drivers/net/wwan/iosm/iosm_ipc_imem.h  |  2 --
 drivers/net/wwan/iosm/iosm_ipc_pcie.c  |  4 +---
 drivers/net/wwan/iosm/iosm_ipc_port.c  | 17 +----------------
 drivers/net/wwan/iosm/iosm_ipc_trace.c |  8 --------
 drivers/net/wwan/iosm/iosm_ipc_wwan.c  | 21 ++-------------------
 6 files changed, 4 insertions(+), 65 deletions(-)

diff --git a/drivers/net/wwan/iosm/iosm_ipc_imem.c b/drivers/net/wwan/iosm/iosm_ipc_imem.c
index 635301d677e186..829515a601b379 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_imem.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem.c
@@ -4,7 +4,6 @@
  */
 
 #include <linux/delay.h>
-#include <linux/pm_runtime.h>
 
 #include "iosm_ipc_chnl_cfg.h"
 #include "iosm_ipc_devlink.h"
@@ -632,11 +631,6 @@ static void ipc_imem_run_state_worker(struct work_struct *instance)
 	/* Complete all memory stores after setting bit */
 	smp_mb__after_atomic();
 
-	if (ipc_imem->pcie->pci->device == INTEL_CP_DEVICE_7560_ID) {
-		pm_runtime_mark_last_busy(ipc_imem->dev);
-		pm_runtime_put_autosuspend(ipc_imem->dev);
-	}
-
 	return;
 
 err_ipc_mux_deinit:
@@ -1240,7 +1234,6 @@ void ipc_imem_cleanup(struct iosm_imem *ipc_imem)
 
 	/* forward MDM_NOT_READY to listeners */
 	ipc_uevent_send(ipc_imem->dev, UEVENT_MDM_NOT_READY);
-	pm_runtime_get_sync(ipc_imem->dev);
 
 	hrtimer_cancel(&ipc_imem->td_alloc_timer);
 	hrtimer_cancel(&ipc_imem->tdupdate_timer);
@@ -1426,16 +1419,6 @@ struct iosm_imem *ipc_imem_init(struct iosm_pcie *pcie, unsigned int device_id,
 
 		set_bit(IOSM_DEVLINK_INIT, &ipc_imem->flag);
 	}
-
-	if (!pm_runtime_enabled(ipc_imem->dev))
-		pm_runtime_enable(ipc_imem->dev);
-
-	pm_runtime_set_autosuspend_delay(ipc_imem->dev,
-					 IPC_MEM_AUTO_SUSPEND_DELAY_MS);
-	pm_runtime_use_autosuspend(ipc_imem->dev);
-	pm_runtime_allow(ipc_imem->dev);
-	pm_runtime_mark_last_busy(ipc_imem->dev);
-
 	return ipc_imem;
 devlink_channel_fail:
 	ipc_devlink_deinit(ipc_imem->ipc_devlink);
diff --git a/drivers/net/wwan/iosm/iosm_ipc_imem.h b/drivers/net/wwan/iosm/iosm_ipc_imem.h
index 0144b45e2afb39..5664ac507c902e 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_imem.h
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem.h
@@ -103,8 +103,6 @@ struct ipc_chnl_cfg;
 #define FULLY_FUNCTIONAL 0
 #define IOSM_DEVLINK_INIT 1
 
-#define IPC_MEM_AUTO_SUSPEND_DELAY_MS 5000
-
 /* List of the supported UL/DL pipes. */
 enum ipc_mem_pipes {
 	IPC_MEM_PIPE_0 = 0,
diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
index 3a259c9abefdfa..04517bd3325a2a 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_pcie.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
@@ -6,7 +6,6 @@
 #include <linux/acpi.h>
 #include <linux/bitfield.h>
 #include <linux/module.h>
-#include <linux/pm_runtime.h>
 #include <net/rtnetlink.h>
 
 #include "iosm_ipc_imem.h"
@@ -438,8 +437,7 @@ static int __maybe_unused ipc_pcie_resume_cb(struct device *dev)
 	return 0;
 }
 
-static DEFINE_RUNTIME_DEV_PM_OPS(iosm_ipc_pm, ipc_pcie_suspend_cb,
-				 ipc_pcie_resume_cb, NULL);
+static SIMPLE_DEV_PM_OPS(iosm_ipc_pm, ipc_pcie_suspend_cb, ipc_pcie_resume_cb);
 
 static struct pci_driver iosm_ipc_driver = {
 	.name = KBUILD_MODNAME,
diff --git a/drivers/net/wwan/iosm/iosm_ipc_port.c b/drivers/net/wwan/iosm/iosm_ipc_port.c
index 2ba1ddca3945b2..5d5b4183e14a3a 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_port.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_port.c
@@ -3,8 +3,6 @@
  * Copyright (C) 2020-21 Intel Corporation.
  */
 
-#include <linux/pm_runtime.h>
-
 #include "iosm_ipc_chnl_cfg.h"
 #include "iosm_ipc_imem_ops.h"
 #include "iosm_ipc_port.h"
@@ -15,16 +13,12 @@ static int ipc_port_ctrl_start(struct wwan_port *port)
 	struct iosm_cdev *ipc_port = wwan_port_get_drvdata(port);
 	int ret = 0;
 
-	pm_runtime_get_sync(ipc_port->ipc_imem->dev);
 	ipc_port->channel = ipc_imem_sys_port_open(ipc_port->ipc_imem,
 						   ipc_port->chl_id,
 						   IPC_HP_CDEV_OPEN);
 	if (!ipc_port->channel)
 		ret = -EIO;
 
-	pm_runtime_mark_last_busy(ipc_port->ipc_imem->dev);
-	pm_runtime_put_autosuspend(ipc_port->ipc_imem->dev);
-
 	return ret;
 }
 
@@ -33,24 +27,15 @@ static void ipc_port_ctrl_stop(struct wwan_port *port)
 {
 	struct iosm_cdev *ipc_port = wwan_port_get_drvdata(port);
 
-	pm_runtime_get_sync(ipc_port->ipc_imem->dev);
 	ipc_imem_sys_port_close(ipc_port->ipc_imem, ipc_port->channel);
-	pm_runtime_mark_last_busy(ipc_port->ipc_imem->dev);
-	pm_runtime_put_autosuspend(ipc_port->ipc_imem->dev);
 }
 
 /* transfer control data to modem */
 static int ipc_port_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
 {
 	struct iosm_cdev *ipc_port = wwan_port_get_drvdata(port);
-	int ret;
 
-	pm_runtime_get_sync(ipc_port->ipc_imem->dev);
-	ret = ipc_imem_sys_cdev_write(ipc_port, skb);
-	pm_runtime_mark_last_busy(ipc_port->ipc_imem->dev);
-	pm_runtime_put_autosuspend(ipc_port->ipc_imem->dev);
-
-	return ret;
+	return ipc_imem_sys_cdev_write(ipc_port, skb);
 }
 
 static const struct wwan_port_ops ipc_wwan_ctrl_ops = {
diff --git a/drivers/net/wwan/iosm/iosm_ipc_trace.c b/drivers/net/wwan/iosm/iosm_ipc_trace.c
index 4368373797b69b..eeecfa3d10c5ab 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_trace.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_trace.c
@@ -3,9 +3,7 @@
  * Copyright (C) 2020-2021 Intel Corporation.
  */
 
-#include <linux/pm_runtime.h>
 #include <linux/wwan.h>
-
 #include "iosm_ipc_trace.h"
 
 /* sub buffer size and number of sub buffer */
@@ -99,8 +97,6 @@ static ssize_t ipc_trace_ctrl_file_write(struct file *filp,
 	if (ret)
 		return ret;
 
-	pm_runtime_get_sync(ipc_trace->ipc_imem->dev);
-
 	mutex_lock(&ipc_trace->trc_mutex);
 	if (val == TRACE_ENABLE && ipc_trace->mode != TRACE_ENABLE) {
 		ipc_trace->channel = ipc_imem_sys_port_open(ipc_trace->ipc_imem,
@@ -121,10 +117,6 @@ static ssize_t ipc_trace_ctrl_file_write(struct file *filp,
 	ret = count;
 unlock:
 	mutex_unlock(&ipc_trace->trc_mutex);
-
-	pm_runtime_mark_last_busy(ipc_trace->ipc_imem->dev);
-	pm_runtime_put_autosuspend(ipc_trace->ipc_imem->dev);
-
 	return ret;
 }
 
diff --git a/drivers/net/wwan/iosm/iosm_ipc_wwan.c b/drivers/net/wwan/iosm/iosm_ipc_wwan.c
index 93d17de08786c2..ff747fc79aaf80 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_wwan.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_wwan.c
@@ -6,7 +6,6 @@
 #include <linux/etherdevice.h>
 #include <linux/if_arp.h>
 #include <linux/if_link.h>
-#include <linux/pm_runtime.h>
 #include <linux/rtnetlink.h>
 #include <linux/wwan.h>
 #include <net/pkt_sched.h>
@@ -52,13 +51,11 @@ static int ipc_wwan_link_open(struct net_device *netdev)
 	struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
 	struct iosm_wwan *ipc_wwan = priv->ipc_wwan;
 	int if_id = priv->if_id;
-	int ret = 0;
 
 	if (if_id < IP_MUX_SESSION_START ||
 	    if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
 		return -EINVAL;
 
-	pm_runtime_get_sync(ipc_wwan->ipc_imem->dev);
 	/* get channel id */
 	priv->ch_id = ipc_imem_sys_wwan_open(ipc_wwan->ipc_imem, if_id);
 
@@ -66,8 +63,7 @@ static int ipc_wwan_link_open(struct net_device *netdev)
 		dev_err(ipc_wwan->dev,
 			"cannot connect wwan0 & id %d to the IPC mem layer",
 			if_id);
-		ret = -ENODEV;
-		goto err_out;
+		return -ENODEV;
 	}
 
 	/* enable tx path, DL data may follow */
@@ -76,11 +72,7 @@ static int ipc_wwan_link_open(struct net_device *netdev)
 	dev_dbg(ipc_wwan->dev, "Channel id %d allocated to if_id %d",
 		priv->ch_id, priv->if_id);
 
-err_out:
-	pm_runtime_mark_last_busy(ipc_wwan->ipc_imem->dev);
-	pm_runtime_put_autosuspend(ipc_wwan->ipc_imem->dev);
-
-	return ret;
+	return 0;
 }
 
 /* Bring-down the wwan net link */
@@ -90,12 +82,9 @@ static int ipc_wwan_link_stop(struct net_device *netdev)
 
 	netif_stop_queue(netdev);
 
-	pm_runtime_get_sync(priv->ipc_wwan->ipc_imem->dev);
 	ipc_imem_sys_wwan_close(priv->ipc_wwan->ipc_imem, priv->if_id,
 				priv->ch_id);
 	priv->ch_id = -1;
-	pm_runtime_mark_last_busy(priv->ipc_wwan->ipc_imem->dev);
-	pm_runtime_put_autosuspend(priv->ipc_wwan->ipc_imem->dev);
 
 	return 0;
 }
@@ -117,7 +106,6 @@ static netdev_tx_t ipc_wwan_link_transmit(struct sk_buff *skb,
 	    if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
 		return -EINVAL;
 
-	pm_runtime_get(ipc_wwan->ipc_imem->dev);
 	/* Send the SKB to device for transmission */
 	ret = ipc_imem_sys_wwan_transmit(ipc_wwan->ipc_imem,
 					 if_id, priv->ch_id, skb);
@@ -131,14 +119,9 @@ static netdev_tx_t ipc_wwan_link_transmit(struct sk_buff *skb,
 		ret = NETDEV_TX_BUSY;
 		dev_err(ipc_wwan->dev, "unable to push packets");
 	} else {
-		pm_runtime_mark_last_busy(ipc_wwan->ipc_imem->dev);
-		pm_runtime_put_autosuspend(ipc_wwan->ipc_imem->dev);
 		goto exit;
 	}
 
-	pm_runtime_mark_last_busy(ipc_wwan->ipc_imem->dev);
-	pm_runtime_put_autosuspend(ipc_wwan->ipc_imem->dev);
-
 	return ret;
 
 exit:

base-commit: 2b10740ce74abaea31c2cad4ff8e180549c4544b
-- 
An old man doll... just what I always wanted! - Clara