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mei: use hbm idle state to prevent spurious resets

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When reset is caused by hbm protocol mismatch or timeout
we might end up in an endless reset loop and hbm protocol
will never sync

Cc: <stable@vger.kernel.org>
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>
This commit is contained in:
Tomas Winkler 2014-01-08 20:19:22 +02:00 committed by Greg Kroah-Hartman
parent 544f946014
commit 66ae460b13
4 changed files with 43 additions and 14 deletions
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19
drivers/misc/mei/hbm.c
View File

@ -126,6 +126,17 @@ static bool is_treat_specially_client(struct mei_cl *cl,
return false;
}
/**
* mei_hbm_idle - set hbm to idle state
*
* @dev: the device structure
*/
void mei_hbm_idle(struct mei_device *dev)
{
dev->init_clients_timer = 0;
dev->hbm_state = MEI_HBM_IDLE;
}
int mei_hbm_start_wait(struct mei_device *dev)
{
int ret;
@ -583,6 +594,14 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
/* ignore spurious message and prevent reset nesting
* hbm is put to idle during system reset
*/
if (dev->hbm_state == MEI_HBM_IDLE) {
dev_dbg(&dev->pdev->dev, "hbm: state is idle ignore spurious messages\n");
return 0;
}
switch (mei_msg->hbm_cmd) {
case HOST_START_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: start: response message received.\n");

1
drivers/misc/mei/hbm.h
View File

@ -49,6 +49,7 @@ static inline void mei_hbm_hdr(struct mei_msg_hdr *hdr, size_t length)
hdr->reserved = 0;
}
void mei_hbm_idle(struct mei_device *dev);
int mei_hbm_start_req(struct mei_device *dev);
int mei_hbm_start_wait(struct mei_device *dev);
int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl);

12
drivers/misc/mei/init.c
View File

@ -129,14 +129,19 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
mei_dev_state_str(dev->dev_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);
ret = mei_hw_reset(dev, interrupts_enabled);
if (ret) {
dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
interrupts_enabled = false;
dev->dev_state = MEI_DEV_DISABLED;
}
dev->hbm_state = MEI_HBM_IDLE;
if (dev->dev_state != MEI_DEV_INITIALIZING &&
dev->dev_state != MEI_DEV_POWER_UP) {
@ -160,8 +165,6 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
}
/* we're already in reset, cancel the init timer */
dev->init_clients_timer = 0;
dev->me_clients_num = 0;
dev->rd_msg_hdr = 0;
@ -169,6 +172,7 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
if (!interrupts_enabled) {
dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
dev->dev_state = MEI_DEV_DISABLED;
return;
}

25
drivers/misc/mei/interrupt.c
View File

@ -537,7 +537,6 @@ EXPORT_SYMBOL_GPL(mei_irq_write_handler);
*
* @work: pointer to the work_struct structure
*
* NOTE: This function is called by timer interrupt work
*/
void mei_timer(struct work_struct *work)
{
@ -552,18 +551,24 @@ void mei_timer(struct work_struct *work)
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
if (dev->dev_state == MEI_DEV_INIT_CLIENTS) {
if (dev->init_clients_timer) {
if (--dev->init_clients_timer == 0) {
dev_err(&dev->pdev->dev, "reset: init clients timeout hbm_state = %d.\n",
dev->hbm_state);
mei_reset(dev, 1);
}
/* Catch interrupt stalls during HBM init handshake */
if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
dev->hbm_state != MEI_HBM_IDLE) {
if (dev->init_clients_timer) {
if (--dev->init_clients_timer == 0) {
dev_err(&dev->pdev->dev, "timer: init clients timeout hbm_state = %d.\n",
dev->hbm_state);
mei_reset(dev, 1);
goto out;
}
}
goto out;
}
if (dev->dev_state != MEI_DEV_ENABLED)
goto out;
/*** connect/disconnect timeouts ***/
list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
if (cl_pos->timer_count) {