4.19-stable patches

added patches:
	hwmon-lm90-fix-max6658-sporadic-wrong-temperature-reading.patch

diff --git a/queue-4.19/hwmon-lm90-fix-max6658-sporadic-wrong-temperature-reading.patch b/queue-4.19/hwmon-lm90-fix-max6658-sporadic-wrong-temperature-reading.patch
new file mode 100644 (file)
index 0000000..51dec79
--- /dev/null
+++ b/queue-4.19/hwmon-lm90-fix-max6658-sporadic-wrong-temperature-reading.patch
@@ -0,0 +1,120 @@
+From 62456189f3292c62f87aef363f204886dc1d4b48 Mon Sep 17 00:00:00 2001
+From: Boyang Yu <byu@arista.com>
+Date: Fri, 28 Jun 2019 19:06:36 +0000
+Subject: hwmon: (lm90) Fix max6658 sporadic wrong temperature reading
+
+From: Boyang Yu <byu@arista.com>
+
+commit 62456189f3292c62f87aef363f204886dc1d4b48 upstream.
+
+max6658 may report unrealistically high temperature during
+the driver initialization, for which, its overtemp alarm pin
+also gets asserted. For certain devices implementing overtemp
+protection based on that pin, it may further trigger a reset to
+the device. By reproducing the problem, the wrong reading is
+found to be coincident with changing the conversion rate.
+
+To mitigate this issue, set the stop bit before changing the
+conversion rate and unset it thereafter. After such change, the
+wrong reading is not reproduced. Apply this change only to the
+max6657 kind for now, controlled by flag LM90_PAUSE_ON_CONFIG.
+
+Signed-off-by: Boyang Yu <byu@arista.com>
+Signed-off-by: Guenter Roeck <linux@roeck-us.net>
+Cc: Paul Menzel <pmenzel@molgen.mpg.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/hwmon/lm90.c |   42 ++++++++++++++++++++++++++++++++++++++----
+ 1 file changed, 38 insertions(+), 4 deletions(-)
+
+--- a/drivers/hwmon/lm90.c
++++ b/drivers/hwmon/lm90.c
+@@ -187,6 +187,7 @@ enum chips { lm90, adm1032, lm99, lm86,
+ #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm          */
+ #define LM90_HAVE_TEMP3               (1 << 6) /* 3rd temperature sensor      */
+ #define LM90_HAVE_BROKEN_ALERT        (1 << 7) /* Broken alert                */
++#define LM90_PAUSE_FOR_CONFIG (1 << 8) /* Pause conversion for config */
+ 
+ /* LM90 status */
+ #define LM90_STATUS_LTHRM     (1 << 0) /* local THERM limit tripped */
+@@ -380,6 +381,7 @@ static const struct lm90_params lm90_par
+               .reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
+       },
+       [max6657] = {
++              .flags = LM90_PAUSE_FOR_CONFIG,
+               .alert_alarms = 0x7c,
+               .max_convrate = 8,
+               .reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
+@@ -580,6 +582,38 @@ static inline int lm90_select_remote_cha
+       return 0;
+ }
+ 
++static int lm90_write_convrate(struct i2c_client *client,
++                             struct lm90_data *data, int val)
++{
++      int err;
++      int config_orig, config_stop;
++
++      /* Save config and pause conversion */
++      if (data->flags & LM90_PAUSE_FOR_CONFIG) {
++              config_orig = lm90_read_reg(client, LM90_REG_R_CONFIG1);
++              if (config_orig < 0)
++                      return config_orig;
++              config_stop = config_orig | 0x40;
++              if (config_orig != config_stop) {
++                      err = i2c_smbus_write_byte_data(client,
++                                                      LM90_REG_W_CONFIG1,
++                                                      config_stop);
++                      if (err < 0)
++                              return err;
++              }
++      }
++
++      /* Set conv rate */
++      err = i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, val);
++
++      /* Revert change to config */
++      if (data->flags & LM90_PAUSE_FOR_CONFIG && config_orig != config_stop)
++              i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
++                                        config_orig);
++
++      return err;
++}
++
+ /*
+  * Set conversion rate.
+  * client->update_lock must be held when calling this function (unless we are
+@@ -600,7 +634,7 @@ static int lm90_set_convrate(struct i2c_
+               if (interval >= update_interval * 3 / 4)
+                       break;
+ 
+-      err = i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
++      err = lm90_write_convrate(client, data, i);
+       data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
+       return err;
+ }
+@@ -1606,8 +1640,7 @@ static void lm90_restore_conf(void *_dat
+       struct i2c_client *client = data->client;
+ 
+       /* Restore initial configuration */
+-      i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
+-                                data->convrate_orig);
++      lm90_write_convrate(client, data, data->convrate_orig);
+       i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
+                                 data->config_orig);
+ }
+@@ -1624,12 +1657,13 @@ static int lm90_init_client(struct i2c_c
+       /*
+        * Start the conversions.
+        */
+-      lm90_set_convrate(client, data, 500);   /* 500ms; 2Hz conversion rate */
+       config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
+       if (config < 0)
+               return config;
+       data->config_orig = config;
+ 
++      lm90_set_convrate(client, data, 500); /* 500ms; 2Hz conversion rate */
++
+       /* Check Temperature Range Select */
+       if (data->kind == adt7461 || data->kind == tmp451) {
+               if (config & 0x04)

diff --git a/queue-4.19/series b/queue-4.19/series
index 20c608e28c2b4c2ce72d4f04b57d92ad420d8653..be8babe602555f764bd9e983f9d9abc756c250b9 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -113,3 +113,4 @@ prctl-fix-pr_set_mm_auxv-kernel-stack-leak.patch
 powerpc-64s-fix-instruction-encoding-for-lis-in-ppc_function_entry.patch
 binfmt_misc-fix-possible-deadlock-in-bm_register_write.patch
 x86-unwind-orc-disable-kasan-checking-in-the-orc-unwinder-part-2.patch
+hwmon-lm90-fix-max6658-sporadic-wrong-temperature-reading.patch