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authorAndres Salomon <dilinger@queued.net>2012-07-13 15:54:25 -0700
committerAndres Salomon <dilinger@queued.net>2012-07-31 23:27:30 -0400
commitd278b7a2f90f91f908b19b50cfa59e10632b5afc (patch)
tree559ebe7c5cfbdb46381ecd9074dff292c09f7012 /drivers/platform/olpc
parentac2504151f5af27bbf0c0362b7da5951e05dfc43 (diff)
downloadlinux-d278b7a2f90f91f908b19b50cfa59e10632b5afc.tar.gz
Platform: OLPC: add a suspended flag to the EC driver
A problem we've noticed on XO-1.75 is when we suspend in the middle of an EC command. Don't allow that. In the process, create a private object for the generic EC driver to use; we have a framework for passing around a struct, use that rather than a proliferation of global variables. Signed-off-by: Andres Salomon <dilinger@queued.net> Acked-by: Paul Fox <pgf@laptop.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/platform/olpc')
-rw-r--r--drivers/platform/olpc/olpc-ec.c46
1 files changed, 45 insertions, 1 deletions
diff --git a/drivers/platform/olpc/olpc-ec.c b/drivers/platform/olpc/olpc-ec.c
index d00523c6519..cfba41fb04d 100644
--- a/drivers/platform/olpc/olpc-ec.c
+++ b/drivers/platform/olpc/olpc-ec.c
@@ -9,6 +9,7 @@
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
+#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/module.h>
#include <linux/list.h>
@@ -27,6 +28,21 @@ struct ec_cmd_desc {
void *priv;
};
+struct olpc_ec_priv {
+ struct olpc_ec_driver *drv;
+
+ /*
+ * Running an EC command while suspending means we don't always finish
+ * the command before the machine suspends. This means that the EC
+ * is expecting the command protocol to finish, but we after a period
+ * of time (while the OS is asleep) the EC times out and restarts its
+ * idle loop. Meanwhile, the OS wakes up, thinks it's still in the
+ * middle of the command protocol, starts throwing random things at
+ * the EC... and everyone's uphappy.
+ */
+ bool suspended;
+};
+
static void olpc_ec_worker(struct work_struct *w);
static DECLARE_WORK(ec_worker, olpc_ec_worker);
@@ -34,6 +50,7 @@ static LIST_HEAD(ec_cmd_q);
static DEFINE_SPINLOCK(ec_cmd_q_lock);
static struct olpc_ec_driver *ec_driver;
+static struct olpc_ec_priv *ec_priv;
static void *ec_cb_arg;
static DEFINE_MUTEX(ec_cb_lock);
@@ -93,6 +110,7 @@ static void queue_ec_descriptor(struct ec_cmd_desc *desc)
int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, size_t outlen)
{
+ struct olpc_ec_priv *ec = ec_priv;
struct ec_cmd_desc desc;
/* XXX: this will be removed in later patches */
@@ -104,6 +122,13 @@ int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, size_t outlen)
if (WARN_ON(!ec_driver || !ec_driver->ec_cmd))
return -ENODEV;
+ if (!ec)
+ return -ENOMEM;
+
+ /* Suspending in the middle of a command hoses things really badly */
+ if (WARN_ON(ec->suspended))
+ return -EBUSY;
+
might_sleep();
desc.cmd = cmd;
@@ -126,11 +151,19 @@ EXPORT_SYMBOL_GPL(olpc_ec_cmd);
static int olpc_ec_probe(struct platform_device *pdev)
{
+ struct olpc_ec_priv *ec;
int err;
if (!ec_driver)
return -ENODEV;
+ ec = kzalloc(sizeof(*ec), GFP_KERNEL);
+ if (!ec)
+ return -ENOMEM;
+ ec->drv = ec_driver;
+ ec_priv = ec;
+ platform_set_drvdata(pdev, ec);
+
err = ec_driver->probe ? ec_driver->probe(pdev) : 0;
return err;
@@ -139,12 +172,23 @@ static int olpc_ec_probe(struct platform_device *pdev)
static int olpc_ec_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
- return ec_driver->suspend ? ec_driver->suspend(pdev) : 0;
+ struct olpc_ec_priv *ec = platform_get_drvdata(pdev);
+ int err = 0;
+
+ if (ec_driver->suspend)
+ err = ec_driver->suspend(pdev);
+ if (!err)
+ ec->suspended = true;
+
+ return err;
}
static int olpc_ec_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
+ struct olpc_ec_priv *ec = platform_get_drvdata(pdev);
+
+ ec->suspended = false;
return ec_driver->resume ? ec_driver->resume(pdev) : 0;
}