This is a note to let you know that I've just added the patch titled
i2c: xiic: Switch from waitqueue to completion
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-xiic-switch-from-waitqueue-to-completion.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2b5afccf251f984e5dd4115ca62d16405c7833f8
Author: Marek Vasut <marex@xxxxxxx>
Date: Mon Aug 23 23:41:43 2021 +0200
i2c: xiic: Switch from waitqueue to completion
[ Upstream commit fdacc3c7405d1fc33c1f2771699a4fc24551e480 ]
There will never be threads queueing up in the xiic_xmit(), use
completion synchronization primitive to wait for the interrupt
handler thread to complete instead as it is much better fit and
there is no need to overload it for this purpose.
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Acked-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Stable-dep-of: 1d4a1adbed25 ("i2c: xiic: Try re-initialization on bus busy timeout")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index ae9ef3f7220e6..c6447b2769f9d 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -23,7 +23,7 @@
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
-#include <linux/wait.h>
+#include <linux/completion.h>
#include <linux/platform_data/i2c-xiic.h>
#include <linux/io.h>
#include <linux/slab.h>
@@ -48,7 +48,7 @@ enum xiic_endian {
* struct xiic_i2c - Internal representation of the XIIC I2C bus
* @dev: Pointer to device structure
* @base: Memory base of the HW registers
- * @wait: Wait queue for callers
+ * @completion: Completion for callers
* @adap: Kernel adapter representation
* @tx_msg: Messages from above to be sent
* @lock: Mutual exclusion
@@ -64,7 +64,7 @@ enum xiic_endian {
struct xiic_i2c {
struct device *dev;
void __iomem *base;
- wait_queue_head_t wait;
+ struct completion completion;
struct i2c_adapter adap;
struct i2c_msg *tx_msg;
struct mutex lock;
@@ -160,6 +160,9 @@ struct xiic_i2c {
#define XIIC_PM_TIMEOUT 1000 /* ms */
/* timeout waiting for the controller to respond */
#define XIIC_I2C_TIMEOUT (msecs_to_jiffies(1000))
+/* timeout waiting for the controller finish transfers */
+#define XIIC_XFER_TIMEOUT (msecs_to_jiffies(10000))
+
/*
* The following constant is used for the device global interrupt enable
* register, to enable all interrupts for the device, this is the only bit
@@ -367,7 +370,7 @@ static void xiic_wakeup(struct xiic_i2c *i2c, int code)
i2c->rx_msg = NULL;
i2c->nmsgs = 0;
i2c->state = code;
- wake_up(&i2c->wait);
+ complete(&i2c->completion);
}
static irqreturn_t xiic_process(int irq, void *dev_id)
@@ -714,6 +717,7 @@ static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num)
i2c->tx_msg = msgs;
i2c->rx_msg = NULL;
i2c->nmsgs = num;
+ init_completion(&i2c->completion);
ret = xiic_reinit(i2c);
if (!ret)
@@ -740,23 +744,23 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
err = xiic_start_xfer(i2c, msgs, num);
if (err < 0) {
dev_err(adap->dev.parent, "Error xiic_start_xfer\n");
- goto out;
+ return err;
}
- if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
- (i2c->state == STATE_DONE), HZ)) {
- mutex_lock(&i2c->lock);
- err = (i2c->state == STATE_DONE) ? num : -EIO;
- goto out;
- } else {
- mutex_lock(&i2c->lock);
+ err = wait_for_completion_timeout(&i2c->completion, XIIC_XFER_TIMEOUT);
+ mutex_lock(&i2c->lock);
+ if (err == 0) { /* Timeout */
i2c->tx_msg = NULL;
i2c->rx_msg = NULL;
i2c->nmsgs = 0;
err = -ETIMEDOUT;
- goto out;
+ } else if (err < 0) { /* Completion error */
+ i2c->tx_msg = NULL;
+ i2c->rx_msg = NULL;
+ i2c->nmsgs = 0;
+ } else {
+ err = (i2c->state == STATE_DONE) ? num : -EIO;
}
-out:
mutex_unlock(&i2c->lock);
pm_runtime_mark_last_busy(i2c->dev);
pm_runtime_put_autosuspend(i2c->dev);
@@ -819,7 +823,6 @@ static int xiic_i2c_probe(struct platform_device *pdev)
DRIVER_NAME " %s", pdev->name);
mutex_init(&i2c->lock);
- init_waitqueue_head(&i2c->wait);
i2c->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c->clk)) {
