Commit dee5d542 authored by Nicholas Kazlauskas's avatar Nicholas Kazlauskas Committed by Alex Deucher
Browse files

drm/amd/display: Read inst_fb data back during DMUB loading 



[Why]
The inst firmware isn't necessarily fully flushed to framebuffer
memory and the DMCUB can hang due to invalid inst being parsed.

[How]
Like the fix to flush ringbuffer commands before updating the inbox
write pointer we need to read back inst memory before writing the
CW0 registers.

Add a helper to read 64-byte chunks to avoid a large temporary buffer.
Read the remaining leftover bytes if the inst_fb isn't fully aligned.

Signed-off-by: default avatarNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: default avatarTony Cheng <Tony.Cheng@amd.com>
Acked-by: default avatarHarry Wentland <harry.wentland@amd.com>
Acked-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent b7408a06

drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c

+27 −0
Original line number Diff line number Diff line
@@ -67,6 +67,26 @@ static inline uint32_t dmub_align(uint32_t val, uint32_t factor) 
	return (val + factor - 1) / factor * factor;

}



static void dmub_flush_buffer_mem(const struct dmub_fb *fb)

{

	const uint8_t *base = (const uint8_t *)fb->cpu_addr;

	uint8_t buf[64];

	uint32_t pos, end;



	/**

	 * Read 64-byte chunks since we don't want to store a

	 * large temporary buffer for this purpose.

	 */

	end = fb->size / sizeof(buf) * sizeof(buf);



	for (pos = 0; pos < end; pos += sizeof(buf))

		dmub_memcpy(buf, base + pos, sizeof(buf));



	/* Read anything leftover into the buffer. */

	if (end < fb->size)

		dmub_memcpy(buf, base + pos, fb->size - end);

}



static const struct dmub_fw_meta_info *

dmub_get_fw_meta_info(const uint8_t *fw_bss_data, uint32_t fw_bss_data_size)

{
@@ -329,6 +349,13 @@ enum dmub_status dmub_srv_hw_init(struct dmub_srv *dmub, 
		cw1.region.base = DMUB_CW1_BASE;

		cw1.region.top = cw1.region.base + stack_fb->size - 1;



		/**

		 * Read back all the instruction memory so we don't hang the

		 * DMCUB when backdoor loading if the write from x86 hasn't been

		 * flushed yet. This only occurs in backdoor loading.

		 */

		dmub_flush_buffer_mem(inst_fb);



		if (params->load_inst_const && dmub->hw_funcs.backdoor_load)

			dmub->hw_funcs.backdoor_load(dmub, &cw0, &cw1);

	}

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