Merge tag 'char-misc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc driver updates from Greg KH:
 "Here is the "large" pull request for char and misc and other assorted
  smaller driver subsystems for 5.3-rc1.

  It seems that this tree is becoming the funnel point of lots of
  smaller driver subsystems, which is fine for me, but that's why it is
  getting larger over time and does not just contain stuff under
  drivers/char/ and drivers/misc.

  Lots of small updates all over the place here from different driver
  subsystems:
   - habana driver updates
   - coresight driver updates
   - documentation file movements and updates
   - Android binder fixes and updates
   - extcon driver updates
   - google firmware driver updates
   - fsi driver updates
   - smaller misc and char driver updates
   - soundwire driver updates
   - nvmem driver updates
   - w1 driver fixes

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (188 commits)
  coresight: Do not default to CPU0 for missing CPU phandle
  dt-bindings: coresight: Change CPU phandle to required property
  ocxl: Allow contexts to be attached with a NULL mm
  fsi: sbefifo: Don't fail operations when in SBE IPL state
  coresight: tmc: Smatch: Fix potential NULL pointer dereference
  coresight: etm3x: Smatch: Fix potential NULL pointer dereference
  coresight: Potential uninitialized variable in probe()
  coresight: etb10: Do not call smp_processor_id from preemptible
  coresight: tmc-etf: Do not call smp_processor_id from preemptible
  coresight: tmc-etr: alloc_perf_buf: Do not call smp_processor_id from preemptible
  coresight: tmc-etr: Do not call smp_processor_id() from preemptible
  docs: misc-devices: convert files without extension to ReST
  fpga: dfl: fme: align PR buffer size per PR datawidth
  fpga: dfl: fme: remove copy_to_user() in ioctl for PR
  fpga: dfl-fme-mgr: fix FME_PR_INTFC_ID register address.
  intel_th: msu: Start read iterator from a non-empty window
  intel_th: msu: Split sgt array and pointer in multiwindow mode
  intel_th: msu: Support multipage blocks
  intel_th: pci: Add Ice Lake NNPI support
  intel_th: msu: Fix single mode with disabled IOMMU
  ...

1 files changed, 44 insertions, 21 deletions

diff --git a/drivers/w1/slaves/w1_ds2413.c b/drivers/w1/slaves/w1_ds2413.c
index 5ae74d5545e6..f1fb18afbcea 100644
--- a/drivers/w1/slaves/w1_ds2413.c
+++ b/drivers/w1/slaves/w1_ds2413.c
@@ -22,12 +22,17 @@
 #define W1_F3A_FUNC_PIO_ACCESS_READ        0xF5
 #define W1_F3A_FUNC_PIO_ACCESS_WRITE       0x5A
 #define W1_F3A_SUCCESS_CONFIRM_BYTE        0xAA
+#define W1_F3A_INVALID_PIO_STATE           0xFF
 
 static ssize_t state_read(struct file *filp, struct kobject *kobj,
 			  struct bin_attribute *bin_attr, char *buf, loff_t off,
 			  size_t count)
 {
 	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	unsigned int retries = W1_F3A_RETRIES;
+	ssize_t bytes_read = -EIO;
+	u8 state;
+
 	dev_dbg(&sl->dev,
 		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
 		bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
@@ -40,22 +45,37 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj,
 	mutex_lock(&sl->master->bus_mutex);
 	dev_dbg(&sl->dev, "mutex locked");
 
-	if (w1_reset_select_slave(sl)) {
-		mutex_unlock(&sl->master->bus_mutex);
-		return -EIO;
-	}
+next:
+	if (w1_reset_select_slave(sl))
+		goto out;
+
+	while (retries--) {
+		w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
+
+		state = w1_read_8(sl->master);
+		if ((state & 0x0F) == ((~state >> 4) & 0x0F)) {
+			/* complement is correct */
+			*buf = state;
+			bytes_read = 1;
+			goto out;
+		} else if (state == W1_F3A_INVALID_PIO_STATE) {
+			/* slave didn't respond, try to select it again */
+			dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \
+					    "reselecting, retries left: %d\n", retries);
+			goto next;
+		}
 
-	w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
-	*buf = w1_read_8(sl->master);
+		if (w1_reset_resume_command(sl->master))
+			goto out; /* unrecoverable error */
 
-	mutex_unlock(&sl->master->bus_mutex);
-	dev_dbg(&sl->dev, "mutex unlocked");
+		dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries);
+	}
 
-	/* check for correct complement */
-	if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
-		return -EIO;
-	else
-		return 1;
+out:
+	mutex_unlock(&sl->master->bus_mutex);
+	dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
+		(bytes_read > 0) ? "succeeded" : "error", retries);
+	return bytes_read;
 }
 
 static BIN_ATTR_RO(state, 1);
@@ -67,6 +87,7 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
 	struct w1_slave *sl = kobj_to_w1_slave(kobj);
 	u8 w1_buf[3];
 	unsigned int retries = W1_F3A_RETRIES;
+	ssize_t bytes_written = -EIO;
 
 	if (count != 1 || off != 0)
 		return -EFAULT;
@@ -76,7 +97,7 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
 	dev_dbg(&sl->dev, "mutex locked");
 
 	if (w1_reset_select_slave(sl))
-		goto error;
+		goto out;
 
 	/* according to the DS2413 datasheet the most significant 6 bits
 	   should be set to "1"s, so do it now */
@@ -89,18 +110,20 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
 		w1_write_block(sl->master, w1_buf, 3);
 
 		if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
-			mutex_unlock(&sl->master->bus_mutex);
-			dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
-			return 1;
+			bytes_written = 1;
+			goto out;
 		}
 		if (w1_reset_resume_command(sl->master))
-			goto error;
+			goto out; /* unrecoverable error */
+
+		dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries);
 	}
 
-error:
+out:
 	mutex_unlock(&sl->master->bus_mutex);
-	dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
-	return -EIO;
+	dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
+		(bytes_written > 0) ? "succeeded" : "error", retries);
+	return bytes_written;
 }
 
 static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);