[PATCH 02/10] bus: mhi: pci_generic: Graceful shutdown on freeze

[PATCH 02/10] bus: mhi: pci_generic: Graceful shutdown on freeze

[Manivannan Sadhasivam]

From: Loic Poulain <loic.poulain@linaro.org>

There is no reason for shutting down MHI ungracefully on freeze,
this causes the MHI host stack & device stack to not be aligned
anymore since the proper MHI reset sequence is not performed for
ungraceful shutdown.

Fixes: 5f0c2ee1fe8d ("bus: mhi: pci-generic: Fix hibernation")
Suggested-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1635268180-13699-1-git-send-email-loic.poulain@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/pci_generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index 94d8aa9c2eae..4f72bbcc53c9 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -1021,7 +1021,7 @@ static int __maybe_unused mhi_pci_freeze(struct device *dev)
 	 * context.
 	 */
 	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
-		mhi_power_down(mhi_cntrl, false);
+		mhi_power_down(mhi_cntrl, true);
 		mhi_unprepare_after_power_down(mhi_cntrl);
 	}
 
-- 
2.25.1

[PATCH 06/10] bus: mhi: core: Fix reading wake_capable channel configuration

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <quic_bbhatt@quicinc.com>

The 'wake-capable' entry in channel configuration is not set when
parsing the configuration specified by the controller driver. Add
the missing entry to ensure channel is correctly specified as a
'wake-capable' channel.

Fixes: 0cbf260820fa ("bus: mhi: core: Add support for registering MHI controllers")
Signed-off-by: Bhaumik Bhatt <quic_bbhatt@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1638320491-13382-1-git-send-email-quic_bbhatt@quicinc.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 5aaca6d0f52b..f1ec34417592 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -788,6 +788,7 @@ static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
 		mhi_chan->offload_ch = ch_cfg->offload_channel;
 		mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
 		mhi_chan->pre_alloc = ch_cfg->auto_queue;
+		mhi_chan->wake_capable = ch_cfg->wake_capable;
 
 		/*
 		 * If MHI host allocates buffers, then the channel direction
-- 
2.25.1

[PATCH 07/10] bus: mhi: core: Fix race while handling SYS_ERR at power up

[Manivannan Sadhasivam]

During SYS_ERR condition, as a response to the MHI_RESET from host, some
devices tend to issue BHI interrupt without clearing the SYS_ERR state in
the device. This creates a race condition and causes a failure in booting
up the device.

The issue is seen on the Sierra Wireless EM9191 modem during SYS_ERR
handling in mhi_async_power_up(). Once the host detects that the device
is in SYS_ERR state, it issues MHI_RESET and waits for the device to
process the reset request. During this time, the device triggers the BHI
interrupt to the host without clearing SYS_ERR condition. So the host
starts handling the SYS_ERR condition again.

To fix this issue, let's register the IRQ handler only after handling the
SYS_ERR check to avoid getting spurious IRQs from the device.

Cc: stable@vger.kernel.org
Fixes: e18d4e9fa79b ("bus: mhi: core: Handle syserr during power_up")
Reported-by: Aleksander Morgado <aleksander@aleksander.es>
Tested-by: Aleksander Morgado <aleksander@aleksander.es>
Tested-by: Thomas Perrot <thomas.perrot@bootlin.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/pm.c | 35 ++++++++++++-----------------------
 1 file changed, 12 insertions(+), 23 deletions(-)

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 7464f5d09973..9ae8532df5a3 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -1038,7 +1038,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	enum mhi_ee_type current_ee;
 	enum dev_st_transition next_state;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
-	u32 val;
+	u32 interval_us = 25000; /* poll register field every 25 milliseconds */
 	int ret;
 
 	dev_info(dev, "Requested to power ON\n");
@@ -1055,10 +1055,6 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	mutex_lock(&mhi_cntrl->pm_mutex);
 	mhi_cntrl->pm_state = MHI_PM_DISABLE;
 
-	ret = mhi_init_irq_setup(mhi_cntrl);
-	if (ret)
-		goto error_setup_irq;
-
 	/* Setup BHI INTVEC */
 	write_lock_irq(&mhi_cntrl->pm_lock);
 	mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
@@ -1072,7 +1068,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 		dev_err(dev, "%s is not a valid EE for power on\n",
 			TO_MHI_EXEC_STR(current_ee));
 		ret = -EIO;
-		goto error_async_power_up;
+		goto error_exit;
 	}
 
 	state = mhi_get_mhi_state(mhi_cntrl);
@@ -1081,20 +1077,12 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 
 	if (state == MHI_STATE_SYS_ERR) {
 		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
-		ret = wait_event_timeout(mhi_cntrl->state_event,
-				MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) ||
-					mhi_read_reg_field(mhi_cntrl,
-							   mhi_cntrl->regs,
-							   MHICTRL,
-							   MHICTRL_RESET_MASK,
-							   MHICTRL_RESET_SHIFT,
-							   &val) ||
-					!val,
-				msecs_to_jiffies(mhi_cntrl->timeout_ms));
-		if (!ret) {
-			ret = -EIO;
+		ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
+				 MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0,
+				 interval_us);
+		if (ret) {
 			dev_info(dev, "Failed to reset MHI due to syserr state\n");
-			goto error_async_power_up;
+			goto error_exit;
 		}
 
 		/*
@@ -1104,6 +1092,10 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 		mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
 	}
 
+	ret = mhi_init_irq_setup(mhi_cntrl);
+	if (ret)
+		goto error_exit;
+
 	/* Transition to next state */
 	next_state = MHI_IN_PBL(current_ee) ?
 		DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY;
@@ -1116,10 +1108,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 
 	return 0;
 
-error_async_power_up:
-	mhi_deinit_free_irq(mhi_cntrl);
-
-error_setup_irq:
+error_exit:
 	mhi_cntrl->pm_state = MHI_PM_DISABLE;
 	mutex_unlock(&mhi_cntrl->pm_mutex);
 
-- 
2.25.1