From dee5d542836a911b0175f9cccc25b8f5733e2527 Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas Date: Wed, 11 Dec 2019 21:14:04 -0500 Subject: [PATCH] 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: Nicholas Kazlauskas Reviewed-by: Tony Cheng Acked-by: Harry Wentland Acked-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- .../gpu/drm/amd/display/dmub/src/dmub_srv.c | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c index 23ca1fe97757..dee676335d73 100644 --- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c +++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c @@ -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); } -- 2.30.2