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

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[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: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Nicholas Kazlauskas 2019-12-11 21:14:04 -05:00 committed by Alex Deucher
parent b7408a0673
commit dee5d54283
1 changed files with 27 additions and 0 deletions
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27
drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
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@ -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);
}