Re: [PATCH] drm/amdkfd: Use logical AND operator (&&) instead of bitwise AND (&) with a bool operand

[Lazar, Lijo]

On 12/21/2023 8:12 AM, Srinivasan Shanmugam wrote:
Doing a bitwise AND between a bool and an int is generally not a good
idea.  The bool will be promoted to an int with value 0 or 1, the int is
generally regarded as true with a non-zero value, thus ANDing them using
bitwise has the potential to yield an undesired result.
Thus fixes the below:

drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_packet_manager_v9.c:117 pm_map_process_aldebaran() 
warn: maybe use && instead of &

Cc: Felix Kuehling <felix.kuehl...@amd.com>
Cc: Christian König <christian.koe...@amd.com>
Cc: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>
---
  drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
index 8ee2bedd301a..da83deee45a7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
@@ -114,7 +114,7 @@ static int pm_map_process_aldebaran(struct packet_manager 
*pm,
                        packet->tcp_watch_cntl[i] = pdd->watch_points[i];
  
  		packet->bitfields2.single_memops =
-                               !!(pdd->process->dbg_flags & 
KFD_DBG_TRAP_FLAG_SINGLE_MEM_OP);
+                               !!(pdd->process->dbg_flags && 
KFD_DBG_TRAP_FLAG_SINGLE_MEM_OP);

Logical AND of bool with a known constant doesn't make sense. dbg_flags 
looks to be defined in the wrong way; to process multiple debug flag 
options, better to define as u32.

Thanks,
Lijo

        }
  
  	packet->sh_mem_config = qpd->sh_mem_config;