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, 32 insertions, 11 deletions

diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c
index be3263df278a..6f00c33cfe22 100644
--- a/drivers/misc/eeprom/ee1004.c
+++ b/drivers/misc/eeprom/ee1004.c
@@ -2,7 +2,7 @@
 /*
  * ee1004 - driver for DDR4 SPD EEPROMs
  *
- * Copyright (C) 2017 Jean Delvare
+ * Copyright (C) 2017-2019 Jean Delvare
  *
  * Based on the at24 driver:
  * Copyright (C) 2005-2007 David Brownell
@@ -53,6 +53,24 @@ MODULE_DEVICE_TABLE(i2c, ee1004_ids);
 
 /*-------------------------------------------------------------------------*/
 
+static int ee1004_get_current_page(void)
+{
+	int err;
+
+	err = i2c_smbus_read_byte(ee1004_set_page[0]);
+	if (err == -ENXIO) {
+		/* Nack means page 1 is selected */
+		return 1;
+	}
+	if (err < 0) {
+		/* Anything else is a real error, bail out */
+		return err;
+	}
+
+	/* Ack means page 0 is selected, returned value meaningless */
+	return 0;
+}
+
 static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf,
 				  unsigned int offset, size_t count)
 {
@@ -102,6 +120,16 @@ static ssize_t ee1004_read(struct file *filp, struct kobject *kobj,
 			/* Data is ignored */
 			status = i2c_smbus_write_byte(ee1004_set_page[page],
 						      0x00);
+			if (status == -ENXIO) {
+				/*
+				 * Don't give up just yet. Some memory
+				 * modules will select the page but not
+				 * ack the command. Check which page is
+				 * selected now.
+				 */
+				if (ee1004_get_current_page() == page)
+					status = 0;
+			}
 			if (status < 0) {
 				dev_err(dev, "Failed to select page %d (%d)\n",
 					page, status);
@@ -186,17 +214,10 @@ static int ee1004_probe(struct i2c_client *client,
 	}
 
 	/* Remember current page to avoid unneeded page select */
-	err = i2c_smbus_read_byte(ee1004_set_page[0]);
-	if (err == -ENXIO) {
-		/* Nack means page 1 is selected */
-		ee1004_current_page = 1;
-	} else if (err < 0) {
-		/* Anything else is a real error, bail out */
+	err = ee1004_get_current_page();
+	if (err < 0)
 		goto err_clients;
-	} else {
-		/* Ack means page 0 is selected, returned value meaningless */
-		ee1004_current_page = 0;
-	}
+	ee1004_current_page = err;
 	dev_dbg(&client->dev, "Currently selected page: %d\n",
 		ee1004_current_page);
 	mutex_unlock(&ee1004_bus_lock);