[rtems commit] i2c: Fix return status of i2c dev read/write

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    08135c85d8e868f7eaf9cebeb356fd1b2816995f
Changeset: http://git.rtems.org/rtems/commit/?id=08135c85d8e868f7eaf9cebeb356fd1b2816995f

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Thu Jul 23 09:00:31 2015 +0200

i2c: Fix return status of i2c dev read/write

---

 cpukit/dev/i2c/i2c-dev.c         | 16 ++++++++++------
 testsuites/libtests/i2c01/init.c | 23 +++++++++++++++++++++--
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/cpukit/dev/i2c/i2c-dev.c b/cpukit/dev/i2c/i2c-dev.c
index 6710632..b00a9bd 100644
--- a/cpukit/dev/i2c/i2c-dev.c
+++ b/cpukit/dev/i2c/i2c-dev.c
@@ -43,11 +43,13 @@ static ssize_t i2c_dev_read(
   ssize_t n;
 
   n = (*dev->read)(dev, buffer, count, iop->offset);
-  if (n > 0) {
+  if (n >= 0) {
     iop->offset += n;
-  }
 
-  return n;
+    return n;
+  } else {
+    rtems_set_errno_and_return_minus_one(-n);
+  }
 }
 
 static ssize_t i2c_dev_write(
@@ -60,11 +62,13 @@ static ssize_t i2c_dev_write(
   ssize_t n;
 
   n = (*dev->write)(dev, buffer, count, iop->offset);
-  if (n > 0) {
+  if (n >= 0) {
     iop->offset += n;
-  }
 
-  return n;
+    return n;
+  } else {
+    rtems_set_errno_and_return_minus_one(-n);
+  }
 }
 
 static int i2c_dev_ioctl(
diff --git a/testsuites/libtests/i2c01/init.c b/testsuites/libtests/i2c01/init.c
index ddce494..0d6fc83 100644
--- a/testsuites/libtests/i2c01/init.c
+++ b/testsuites/libtests/i2c01/init.c
@@ -71,6 +71,7 @@ typedef struct {
 
 typedef struct {
   test_device base;
+  bool eio;
   unsigned current_address;
   uint8_t data[EEPROM_SIZE];
 } test_device_eeprom;
@@ -198,6 +199,10 @@ static int test_eeprom_transfer(
   i2c_msg *msg = &msgs[0];
   uint32_t i;
 
+  if (dev->eio) {
+    return -EIO;
+  }
+
   if (msg_count > 0 && (msg->flags & I2C_M_RD) == 0) {
     if (msg->len < 1) {
       return -EIO;
@@ -406,7 +411,7 @@ static void test_gpio_nxp_pca9535(void)
   rtems_test_assert(rv == 0);
 }
 
-static void test_eeprom(void)
+static void test_eeprom(test_bus *bus)
 {
   int rv;
   int fd_in;
@@ -442,6 +447,20 @@ static void test_eeprom(void)
 
   memset(&out[0], 0, sizeof(out));
 
+  bus->eeprom.eio = true;
+
+  errno = 0;
+  n = read(fd_in, &in[0], 1);
+  rtems_test_assert(n == -1);
+  rtems_test_assert(errno == EIO);
+
+  errno = 0;
+  n = write(fd_out, &out[0], 1);
+  rtems_test_assert(n == -1);
+  rtems_test_assert(errno == EIO);
+
+  bus->eeprom.eio = false;
+
   n = read(fd_in, &in[0], sizeof(in) + 1);
   rtems_test_assert(n == (ssize_t) sizeof(in));
 
@@ -608,7 +627,7 @@ static void test(void)
   rtems_test_assert(bus->base.timeout == 0);
 
   test_simple_read_write(bus, fd);
-  test_eeprom();
+  test_eeprom(bus);
   test_gpio_nxp_pca9535();
   test_switch_nxp_pca9548a();