Commit eac61769 authored by Kai Vehmanen's avatar Kai Vehmanen Committed by Carles Cufi
Browse files

logging: adsp_mtrace: fix handling of buffer full condition 



If the mtrace buffer gets full, the entries are dropped. This
is however not reflected in the "bytes_written" argument passed
to the hook function used to notify of new data in the buffer.

This behaviour becomes problematic in the case there is no
active consumer of the mtrace logs. To allow the client that has
registered the hook function, to act correctly in this case,
the bytes_written should reflect the actual bytes that have been
added to buffer.

Signed-off-by: default avatarKai Vehmanen <kai.vehmanen@linux.intel.com>
parent f3fd686b

subsys/logging/log_backend_adsp_mtrace.c

+18 −13
Original line number Diff line number Diff line
@@ -73,13 +73,13 @@ static void mtrace_init(void) 
	ADSP_DW->descs[0].type = MTRACE_LOGGING_SLOT_TYPE(MTRACE_CORE);

}



static void mtrace_out(int8_t *str, size_t len, size_t *space_left)

static size_t mtrace_out(int8_t *str, size_t len, size_t *space_left)

{

	struct adsp_debug_slot *slot = (struct adsp_debug_slot *)(ADSP_DW->slots[0]);

	uint8_t *data = slot->data;

	uint32_t r = slot->host_ptr;

	uint32_t w = slot->dsp_ptr;

	size_t avail, left;

	size_t avail, out;



	if (w > r) {

		avail = MTRACE_LOG_BUF_SIZE - w + r - 1;
@@ -90,22 +90,23 @@ static void mtrace_out(int8_t *str, size_t len, size_t *space_left) 
	}



	if (len == 0) {

		out = 0;

		goto out;

	}



	/* data that does not fit is dropped */

	left = MIN(avail, len);

	out = MIN(avail, len);



	if (w + left >= MTRACE_LOG_BUF_SIZE) {

	if (w + out >= MTRACE_LOG_BUF_SIZE) {

		size_t tail = MTRACE_LOG_BUF_SIZE - w;

		size_t head = out - tail;



		memcpy(data + w, str, tail);

		left -= tail;

		memcpy(data, str + tail, left);

		w = left;

		memcpy(data, str + tail, head);

		w = head;

	} else {

		memcpy(data + w, str, left);

		w += left;

		memcpy(data + w, str, out);

		w += out;

	}



	slot->dsp_ptr = w;
@@ -114,16 +115,20 @@ out: 
	if (space_left) {

		*space_left = avail > len ? avail - len : 0;

	}



	return out;

}



static int char_out(uint8_t *data, size_t length, void *ctx)

{

	size_t space_left = 0;

	size_t out;



	/*

	 * we handle the data even if mtrace is active. this

	 * ensures we can capture early boot messages.

	 * we handle the data even if mtrace notifier is not

	 * active. this ensures we can capture early boot messages.

	 */

	mtrace_out(data, length, &space_left);

	out = mtrace_out(data, length, &space_left);



	if (mtrace_active && mtrace_hook) {
@@ -131,7 +136,7 @@ static int char_out(uint8_t *data, size_t length, void *ctx) 
		if (unlikely(mtrace_panic_mode))

			space_left = 0;



		mtrace_hook(length, space_left);

		mtrace_hook(out, space_left);

	}



	return length;

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