mei: revamp mei reset state machine
1. MEI_DEV_RESETTING device state spans only hardware reset flow
while starting dev state is saved into a local variable for further
reference, this let us to reduce big if statements in case we
are trying to avoid nested resets
2. During initializations if the reset ended in MEI_DEV_DISABLED device
state we bail out with -ENODEV
3. Remove redundant interrupts_enabled parameter as this
can be deduced from the starting dev_state
4. mei_reset propagates error code to the caller
5. Add mei_restart function to wrap the pci resume
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index c47fa27..059133d 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -43,6 +43,113 @@
#undef MEI_DEV_STATE
}
+
+/**
+ * mei_cancel_work. Cancel mei background jobs
+ *
+ * @dev: the device structure
+ *
+ * returns 0 on success or < 0 if the reset hasn't succeeded
+ */
+void mei_cancel_work(struct mei_device *dev)
+{
+ cancel_work_sync(&dev->init_work);
+ cancel_work_sync(&dev->reset_work);
+
+ cancel_delayed_work(&dev->timer_work);
+}
+EXPORT_SYMBOL_GPL(mei_cancel_work);
+
+/**
+ * mei_reset - resets host and fw.
+ *
+ * @dev: the device structure
+ */
+int mei_reset(struct mei_device *dev)
+{
+ enum mei_dev_state state = dev->dev_state;
+ bool interrupts_enabled;
+ int ret;
+
+ if (state != MEI_DEV_INITIALIZING &&
+ state != MEI_DEV_DISABLED &&
+ state != MEI_DEV_POWER_DOWN &&
+ state != MEI_DEV_POWER_UP)
+ dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
+ mei_dev_state_str(state));
+
+ /* we're already in reset, cancel the init timer
+ * if the reset was called due the hbm protocol error
+ * we need to call it before hw start
+ * so the hbm watchdog won't kick in
+ */
+ mei_hbm_idle(dev);
+
+ /* enter reset flow */
+ interrupts_enabled = state != MEI_DEV_POWER_DOWN;
+ dev->dev_state = MEI_DEV_RESETTING;
+
+ ret = mei_hw_reset(dev, interrupts_enabled);
+ /* fall through and remove the sw state even if hw reset has failed */
+
+ /* no need to clean up software state in case of power up */
+ if (state != MEI_DEV_INITIALIZING &&
+ state != MEI_DEV_POWER_UP) {
+
+ /* remove all waiting requests */
+ mei_cl_all_write_clear(dev);
+
+ mei_cl_all_disconnect(dev);
+
+ /* wake up all readers and writers so they can be interrupted */
+ mei_cl_all_wakeup(dev);
+
+ /* remove entry if already in list */
+ dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
+ mei_cl_unlink(&dev->wd_cl);
+ mei_cl_unlink(&dev->iamthif_cl);
+ mei_amthif_reset_params(dev);
+ memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
+ }
+
+
+ dev->me_clients_num = 0;
+ dev->rd_msg_hdr = 0;
+ dev->wd_pending = false;
+
+ if (ret) {
+ dev_err(&dev->pdev->dev, "hw_reset failed ret = %d\n", ret);
+ dev->dev_state = MEI_DEV_DISABLED;
+ return ret;
+ }
+
+ if (state == MEI_DEV_POWER_DOWN) {
+ dev_dbg(&dev->pdev->dev, "powering down: end of reset\n");
+ dev->dev_state = MEI_DEV_DISABLED;
+ return 0;
+ }
+
+ ret = mei_hw_start(dev);
+ if (ret) {
+ dev_err(&dev->pdev->dev, "hw_start failed ret = %d\n", ret);
+ dev->dev_state = MEI_DEV_DISABLED;
+ return ret;
+ }
+
+ dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
+
+ dev->dev_state = MEI_DEV_INIT_CLIENTS;
+ ret = mei_hbm_start_req(dev);
+ if (ret) {
+ dev_err(&dev->pdev->dev, "hbm_start failed ret = %d\n", ret);
+ dev->dev_state = MEI_DEV_DISABLED;
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mei_reset);
+
/**
* mei_start - initializes host and fw to start work.
*
@@ -54,14 +161,20 @@
{
mutex_lock(&dev->device_lock);
- /* acknowledge interrupt and stop interupts */
+ /* acknowledge interrupt and stop interrupts */
mei_clear_interrupts(dev);
mei_hw_config(dev);
dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
- mei_reset(dev, 1);
+ dev->dev_state = MEI_DEV_INITIALIZING;
+ mei_reset(dev);
+
+ if (dev->dev_state == MEI_DEV_DISABLED) {
+ dev_err(&dev->pdev->dev, "reset failed");
+ goto err;
+ }
if (mei_hbm_start_wait(dev)) {
dev_err(&dev->pdev->dev, "HBM haven't started");
@@ -96,106 +209,33 @@
EXPORT_SYMBOL_GPL(mei_start);
/**
- * mei_cancel_work. Cancel mei background jobs
+ * mei_restart - restart device after suspend
*
* @dev: the device structure
- */
-void mei_cancel_work(struct mei_device *dev)
-{
- cancel_work_sync(&dev->init_work);
- cancel_work_sync(&dev->reset_work);
-
- cancel_delayed_work(&dev->timer_work);
-}
-EXPORT_SYMBOL_GPL(mei_cancel_work);
-
-/**
- * mei_reset - resets host and fw.
*
- * @dev: the device structure
- * @interrupts_enabled: if interrupt should be enabled after reset.
+ * returns 0 on success or -ENODEV if the restart hasn't succeeded
*/
-void mei_reset(struct mei_device *dev, int interrupts_enabled)
+int mei_restart(struct mei_device *dev)
{
- bool unexpected;
- int ret;
+ int err;
- unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
- dev->dev_state != MEI_DEV_DISABLED &&
- dev->dev_state != MEI_DEV_POWER_DOWN &&
- dev->dev_state != MEI_DEV_POWER_UP);
+ mutex_lock(&dev->device_lock);
- if (unexpected)
- dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
- mei_dev_state_str(dev->dev_state));
+ mei_clear_interrupts(dev);
- /* we're already in reset, cancel the init timer
- * if the reset was called due the hbm protocol error
- * we need to call it before hw start
- * so the hbm watchdog won't kick in
- */
- mei_hbm_idle(dev);
+ dev->dev_state = MEI_DEV_POWER_UP;
- ret = mei_hw_reset(dev, interrupts_enabled);
- if (ret) {
- dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
- interrupts_enabled = false;
- }
+ err = mei_reset(dev);
+ mutex_unlock(&dev->device_lock);
- if (dev->dev_state != MEI_DEV_INITIALIZING &&
- dev->dev_state != MEI_DEV_POWER_UP) {
- if (dev->dev_state != MEI_DEV_DISABLED &&
- dev->dev_state != MEI_DEV_POWER_DOWN)
- dev->dev_state = MEI_DEV_RESETTING;
+ if (err || dev->dev_state == MEI_DEV_DISABLED)
+ return -ENODEV;
- /* remove all waiting requests */
- mei_cl_all_write_clear(dev);
-
- mei_cl_all_disconnect(dev);
-
- /* wake up all readings so they can be interrupted */
- mei_cl_all_wakeup(dev);
-
- /* remove entry if already in list */
- dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
- mei_cl_unlink(&dev->wd_cl);
- mei_cl_unlink(&dev->iamthif_cl);
- mei_amthif_reset_params(dev);
- memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
- }
-
-
- dev->me_clients_num = 0;
- dev->rd_msg_hdr = 0;
- dev->wd_pending = false;
-
- if (!interrupts_enabled) {
- dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
- dev->dev_state = MEI_DEV_DISABLED;
- return;
- }
-
- ret = mei_hw_start(dev);
- if (ret) {
- dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
- dev->dev_state = MEI_DEV_DISABLED;
- return;
- }
-
- dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
- /* link is established * start sending messages. */
-
- dev->dev_state = MEI_DEV_INIT_CLIENTS;
-
- ret = mei_hbm_start_req(dev);
- if (ret) {
- dev_err(&dev->pdev->dev, "hbm_start failed disabling the device\n");
- dev->dev_state = MEI_DEV_DISABLED;
- return;
- }
+ return 0;
}
-EXPORT_SYMBOL_GPL(mei_reset);
+EXPORT_SYMBOL_GPL(mei_restart);
+
static void mei_reset_work(struct work_struct *work)
{
@@ -204,9 +244,12 @@
mutex_lock(&dev->device_lock);
- mei_reset(dev, true);
+ mei_reset(dev);
mutex_unlock(&dev->device_lock);
+
+ if (dev->dev_state == MEI_DEV_DISABLED)
+ dev_err(&dev->pdev->dev, "reset failed");
}
void mei_stop(struct mei_device *dev)
@@ -222,7 +265,7 @@
mei_wd_stop(dev);
dev->dev_state = MEI_DEV_POWER_DOWN;
- mei_reset(dev, 0);
+ mei_reset(dev);
mutex_unlock(&dev->device_lock);