Update initialization and error handling based on PR feedbacks

docs/how-to/hip_runtime_api/error_handling.rst

@@ -12,10 +12,18 @@ HIP runtime function, apart from launching kernels, has :cpp:type:`hipError_t`
 as return type. :cpp:func:`hipGetLastError()` and :cpp:func:`hipPeekAtLastError()`
 can be used for catching errors from kernel launches, as kernel launches don't
 return an error directly. HIP maintains an internal state, that includes the
-last error code. hipGetLastError returns and resets that error to hipSuccess,
-while :cpp:func:`hipPeekAtLastError` just returns the error without changing it.
-To get a human readable version of the errors, :cpp:func:`hipGetErrorString()`
-and :cpp:func:`hipGetErrorName()` can be used.
+last error code. :cpp:func:`hipGetLastError` returns and resets that error to
+hipSuccess, while :cpp:func:`hipPeekAtLastError` just returns the error without
+changing it. To get a human readable version of the errors,
+:cpp:func:`hipGetErrorString()` and :cpp:func:`hipGetErrorName()` can be used.
+
+.. note::
+
+    :cpp:func:`hipGetLastError` returns the returned error code of the last HIP
+    runtime API call even if it's hipSuccess, while ``cudaGetLastError`` returns
+    the error returned by any of the preceding CUDA APIs in the same host thread.
+    :cpp:func:`hipGetLastError` behavior will be matched with
+    ``cudaGetLastError`` in ROCm release 7.0. 
 
 Best practices of HIP error handling:
 

docs/how-to/hip_runtime_api/initialization.rst

@@ -11,8 +11,11 @@ using GPUs. The following steps are covered with the initialization:
 
 - Setting up the HIP runtime
 
-  This includes loading necessary libraries and setting up internal data
-  structures.
+  This includes reading the environment variables set during init, setting up
+  the active or visible devices, loading necessary libraries, setting up
+  internal buffers for memory copies or cooperative launches, initialize the
+  compiler as well as HSA runtime and checks any errors due to lack of resources
+  or no active devices.
 
 - Querying and setting GPUs