[PATCH v2 05/31] accel/ivpu: Fix fw log printing

[Jacek Lawrynowicz]

  - Fix empty log detection that couldn't work without read_wrap_count
  - Start printing wrapped log from correct position (log_start)
  - Properly handle logs that are wrapped multiple times in reference
    to reader position
  - Don't add a newline when log buffer is wrapped
  - Always add a newline after printing a log buffer in case log does
    not end with one

Signed-off-by: Jacek Lawrynowicz <jacek.lawrynow...@linux.intel.com>
---
 drivers/accel/ivpu/ivpu_fw_log.c | 49 +++++++++++++++++++++-----------
 1 file changed, 32 insertions(+), 17 deletions(-)

diff --git a/drivers/accel/ivpu/ivpu_fw_log.c b/drivers/accel/ivpu/ivpu_fw_log.c
index 343ebfd30d280..337c906b02107 100644
--- a/drivers/accel/ivpu/ivpu_fw_log.c
+++ b/drivers/accel/ivpu/ivpu_fw_log.c
@@ -87,7 +87,7 @@ static void fw_log_print_lines(char *buffer, u32 size, struct 
drm_printer *p)
        }
        line[index] = 0;
        if (index != 0)
-               drm_printf(p, "%s\n", line);
+               drm_printf(p, "%s", line);
 }
 
 static void fw_log_print_buffer(struct vpu_tracing_buffer_header *log, const 
char *prefix,
@@ -95,23 +95,29 @@ static void fw_log_print_buffer(struct 
vpu_tracing_buffer_header *log, const cha
 {
        char *log_data = (void *)log + log->header_size;
        u32 data_size = log->size - log->header_size;
-       u32 log_start = log->read_index;
-       u32 log_end = log->write_index;
+       u32 log_start = only_new_msgs ? READ_ONCE(log->read_index) : 0;
+       u32 log_end = READ_ONCE(log->write_index);
 
-       if (!(log->write_index || log->wrap_count) ||
-           (log->write_index == log->read_index && only_new_msgs)) {
-               drm_printf(p, "==== %s \"%s\" log empty ====\n", prefix, 
log->name);
-               return;
+       if (log->wrap_count == log->read_wrap_count) {
+               if (log_end <= log_start) {
+                       drm_printf(p, "==== %s \"%s\" log empty ====\n", 
prefix, log->name);
+                       return;
+               }
+       } else if (log->wrap_count == log->read_wrap_count + 1) {
+               if (log_end > log_start)
+                       log_start = log_end;
+       } else {
+               log_start = log_end;
        }
 
        drm_printf(p, "==== %s \"%s\" log start ====\n", prefix, log->name);
-       if (log->write_index > log->read_index) {
+       if (log_end > log_start) {
                fw_log_print_lines(log_data + log_start, log_end - log_start, 
p);
        } else {
-               fw_log_print_lines(log_data + log_end, data_size - log_end, p);
+               fw_log_print_lines(log_data + log_start, data_size - log_start, 
p);
                fw_log_print_lines(log_data, log_end, p);
        }
-       drm_printf(p, "\x1b[0m");
+       drm_printf(p, "\n\x1b[0m"); /* add new line and clear formatting */
        drm_printf(p, "==== %s \"%s\" log end   ====\n", prefix, log->name);
 }
 
@@ -135,14 +141,19 @@ void ivpu_fw_log_print(struct ivpu_device *vdev, bool 
only_new_msgs, struct drm_
 void ivpu_fw_log_mark_read(struct ivpu_device *vdev)
 {
        struct vpu_tracing_buffer_header *log;
-       u32 next = 0;
+       u32 next;
 
-       while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &log) == 0)
-               log->read_index = log->write_index;
+       next = 0;
+       while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &log) == 0) {
+               log->read_index = READ_ONCE(log->write_index);
+               log->read_wrap_count = READ_ONCE(log->wrap_count);
+       }
 
        next = 0;
-       while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &log) == 0)
-               log->read_index = log->write_index;
+       while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &log) == 0) {
+               log->read_index = READ_ONCE(log->write_index);
+               log->read_wrap_count = READ_ONCE(log->wrap_count);
+       }
 }
 
 void ivpu_fw_log_reset(struct ivpu_device *vdev)
@@ -151,10 +162,14 @@ void ivpu_fw_log_reset(struct ivpu_device *vdev)
        u32 next;
 
        next = 0;
-       while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &log) == 0)
+       while (fw_log_from_bo(vdev, vdev->fw->mem_log_crit, &next, &log) == 0) {
                log->read_index = 0;
+               log->read_wrap_count = 0;
+       }
 
        next = 0;
-       while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &log) == 0)
+       while (fw_log_from_bo(vdev, vdev->fw->mem_log_verb, &next, &log) == 0) {
                log->read_index = 0;
+               log->read_wrap_count = 0;
+       }
 }
-- 
2.45.1