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Subject[char-misc-next 2/7] mei: amthif: fix request cancel
Date
From: Alexander Usyskin <alexander.usyskin@intel.com>

Currently, all requests cancelled by the user are immediately removed
from the queues. Such removal can cause unexpected behavior in the case
when a request is partially written or a reply is received after the
request is cancelled. To resolve this a request is always fully
processed and the result is discarded in case the request was canceled.
This completes the partial fix in commit:
9d04ee1 ("mei: amthif: discard not read messages")

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
drivers/misc/mei/amthif.c | 111 +++++++++++++++----------------------------
drivers/misc/mei/interrupt.c | 2 -
2 files changed, 38 insertions(+), 75 deletions(-)

diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
index 13d89043ad76..0cded8aa72c0 100644
--- a/drivers/misc/mei/amthif.c
+++ b/drivers/misc/mei/amthif.c
@@ -399,34 +399,44 @@ void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
{
struct mei_device *dev = cl->dev;

- if (cb->fop_type == MEI_FOP_WRITE) {
+ dev_dbg(dev->dev, "completing amthif call back.\n");
+ switch (cb->fop_type) {
+ case MEI_FOP_WRITE:
if (!cb->status) {
dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
mei_io_cb_free(cb);
return;
}
- /*
- * in case of error enqueue the write cb to complete read list
- * so it can be propagated to the reader
- */
- list_add_tail(&cb->list, &cl->rd_completed);
- wake_up_interruptible(&cl->rx_wait);
- return;
- }
+ dev->iamthif_current_cb = NULL;
+ dev->iamthif_state = MEI_IAMTHIF_IDLE;
+ dev->iamthif_fp = NULL;
+ if (!dev->iamthif_canceled) {
+ /*
+ * in case of error enqueue the write cb to complete
+ * read list so it can be propagated to the reader
+ */
+ list_add_tail(&cb->list, &cl->rd_completed);
+ wake_up_interruptible(&cl->rx_wait);
+ } else {
+ mei_io_cb_free(cb);
+ }
+ break;
+ case MEI_FOP_READ:
+ if (!dev->iamthif_canceled) {
+ list_add_tail(&cb->list, &cl->rd_completed);
+ dev_dbg(dev->dev, "amthif read completed\n");
+ wake_up_interruptible(&cl->rx_wait);
+ } else {
+ mei_io_cb_free(cb);
+ }

- if (!dev->iamthif_canceled) {
- list_add_tail(&cb->list, &cl->rd_completed);
- dev_dbg(dev->dev, "amthif read completed\n");
- } else {
- mei_io_cb_free(cb);
+ dev->iamthif_current_cb = NULL;
+ dev->iamthif_stall_timer = 0;
+ mei_amthif_run_next_cmd(dev);
+ break;
+ default:
+ WARN_ON(1);
}
-
- dev->iamthif_current_cb = NULL;
- dev->iamthif_stall_timer = 0;
- mei_amthif_run_next_cmd(dev);
-
- dev_dbg(dev->dev, "completing amthif call back.\n");
- wake_up_interruptible(&cl->rx_wait);
}

/**
@@ -439,32 +449,15 @@ void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
*
* mei_clear_list is called to clear resources associated with file
* when application calls close function or Ctrl-C was pressed
- *
- * Return: true if callback removed from the list, false otherwise
*/
-static bool mei_clear_list(struct mei_device *dev,
+static void mei_clear_list(struct mei_device *dev,
const struct file *file, struct list_head *mei_cb_list)
{
- struct mei_cl *cl = &dev->iamthif_cl;
struct mei_cl_cb *cb, *next;
- bool removed = false;
-
- /* list all list member */
- list_for_each_entry_safe(cb, next, mei_cb_list, list) {
- /* check if list member associated with a file */
- if (file == cb->fp) {
- /* check if cb equal to current iamthif cb */
- if (dev->iamthif_current_cb == cb) {
- dev->iamthif_current_cb = NULL;
- /* send flow control to iamthif client */
- mei_hbm_cl_flow_control_req(dev, cl);
- }
- /* free all allocated buffers */
+
+ list_for_each_entry_safe(cb, next, mei_cb_list, list)
+ if (file == cb->fp)
mei_io_cb_free(cb);
- removed = true;
- }
- }
- return removed;
}

/**
@@ -475,41 +468,14 @@ static bool mei_clear_list(struct mei_device *dev,
*
* mei_clear_lists is called to clear resources associated with file
* when application calls close function or Ctrl-C was pressed
- *
- * Return: true if callback removed from the list, false otherwise
*/
-static bool mei_clear_lists(struct mei_device *dev, const struct file *file)
+static void mei_clear_lists(struct mei_device *dev, const struct file *file)
{
- bool removed = false;
struct mei_cl *cl = &dev->iamthif_cl;

- /* remove callbacks associated with a file */
mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
- if (mei_clear_list(dev, file, &cl->rd_completed))
- removed = true;
-
+ mei_clear_list(dev, file, &cl->rd_completed);
mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
-
- if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
- removed = true;
-
- if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
- removed = true;
-
- if (mei_clear_list(dev, file, &dev->write_list.list))
- removed = true;
-
- /* check if iamthif_current_cb not NULL */
- if (dev->iamthif_current_cb && !removed) {
- /* check file and iamthif current cb association */
- if (dev->iamthif_current_cb->fp == file) {
- /* remove cb */
- mei_io_cb_free(dev->iamthif_current_cb);
- dev->iamthif_current_cb = NULL;
- removed = true;
- }
- }
- return removed;
}

/**
@@ -533,8 +499,7 @@ int mei_amthif_release(struct mei_device *dev, struct file *file)
dev->iamthif_canceled = true;
}

- if (mei_clear_lists(dev, file))
- dev->iamthif_state = MEI_IAMTHIF_IDLE;
+ mei_clear_lists(dev, file);

return 0;
}
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 3831a7ba2531..38db1c3d4f14 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -514,8 +514,6 @@ void mei_timer(struct work_struct *work)
if (--dev->iamthif_stall_timer == 0) {
dev_err(dev->dev, "timer: amthif hanged.\n");
mei_reset(dev);
- dev->iamthif_canceled = false;
- dev->iamthif_state = MEI_IAMTHIF_IDLE;

mei_io_cb_free(dev->iamthif_current_cb);
dev->iamthif_current_cb = NULL;
--
2.5.5
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