[char-misc-next 3/4] mei: pxp: re-enable client on errors

Tomas Winkler
2023-10-11T11:02:32Z

From: Alexander Usyskin <alexander.usyskin@intel.com>

Disable and enable mei-pxp client on errors to clean the internal state.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
drivers/misc/mei/pxp/mei_pxp.c | 70 +++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 22 deletions(-)

diff --git a/drivers/misc/mei/pxp/mei_pxp.c b/drivers/misc/mei/pxp/mei_pxp.c
index c6cdd6a47308ebcc72f34c38..9875d16445bb03efcfb31cd9 100644
--- a/drivers/misc/mei/pxp/mei_pxp.c
+++ b/drivers/misc/mei/pxp/mei_pxp.c
@@ -23,6 +23,24 @@

#include "mei_pxp.h"

+static inline int mei_pxp_reenable(const struct device *dev, struct mei_cl_device *cldev)
+{
+ int ret;
+
+ dev_warn(dev, "Trying to reset the channel...\n");
+ ret = mei_cldev_disable(cldev);
+ if (ret < 0)
+ dev_warn(dev, "mei_cldev_disable failed. %d\n", ret);
+ /*
+ * Explicitly ignoring disable failure,
+ * enable may fix the states and succeed
+ */
+ ret = mei_cldev_enable(cldev);
+ if (ret < 0)
+ dev_err(dev, "mei_cldev_enable failed. %d\n", ret);
+ return ret;
+}
+
/**
* mei_pxp_send_message() - Sends a PXP message to ME FW.
* @dev: device corresponding to the mei_cl_device
@@ -35,6 +53,7 @@ mei_pxp_send_message(struct device *dev, const void *message, size_t size)
{
struct mei_cl_device *cldev;
ssize_t byte;
+ int ret;

if (!dev || !message)
return -EINVAL;
@@ -44,10 +63,20 @@ mei_pxp_send_message(struct device *dev, const void *message, size_t size)
byte = mei_cldev_send(cldev, message, size);
if (byte < 0) {
dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
- return byte;
+ switch (byte) {
+ case -ENOMEM:
+ fallthrough;
+ case -ENODEV:
+ fallthrough;
+ case -ETIME:
+ ret = mei_pxp_reenable(dev, cldev);
+ if (ret)
+ byte = ret;
+ break;
+ }
}

- return 0;
+ return byte;
}

/**
@@ -63,6 +92,7 @@ mei_pxp_receive_message(struct device *dev, void *buffer, size_t size)
struct mei_cl_device *cldev;
ssize_t byte;
bool retry = false;
+ int ret;

if (!dev || !buffer)
return -EINVAL;
@@ -73,26 +103,22 @@ mei_pxp_receive_message(struct device *dev, void *buffer, size_t size)
byte = mei_cldev_recv(cldev, buffer, size);
if (byte < 0) {
dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
- if (byte != -ENOMEM)
- return byte;
-
- /* Retry the read when pages are reclaimed */
- msleep(20);
- if (!retry) {
- retry = true;
- goto retry;
- } else {
- dev_warn(dev, "No memory on data receive after retry, trying to reset the channel...\n");
- byte = mei_cldev_disable(cldev);
- if (byte < 0)
- dev_warn(dev, "mei_cldev_disable failed. %zd\n", byte);
- /*
- * Explicitly ignoring disable failure,
- * enable may fix the states and succeed
- */
- byte = mei_cldev_enable(cldev);
- if (byte < 0)
- dev_err(dev, "mei_cldev_enable failed. %zd\n", byte);
+ switch (byte) {
+ case -ENOMEM:
+ /* Retry the read when pages are reclaimed */
+ msleep(20);
+ if (!retry) {
+ retry = true;
+ goto retry;
+ }
+ fallthrough;
+ case -ENODEV:
+ fallthrough;
+ case -ETIME:
+ ret = mei_pxp_reenable(dev, cldev);
+ if (ret)
+ byte = ret;
+ break;
}
}

--
2.41.0