From: Dillon Varone Dillon.Varone@amd.com
[ Upstream commit 0dfcc2bf269010a6e093793034c048049a40ee93 ]
[WHY] It should no longer use DMCUB_SOFT_RESET as it can result in the memory request path becoming desynchronized.
[HOW] To ensure robustness in the reset sequence: 1) Extend timeout on the "halt" command sent via gpint, and check for controller to enter "wait" as a stronger guarantee that there are no requests to memory still in flight. 2) Remove usage of DMCUB_SOFT_RESET 3) Rely on PSP to reset the controller safely
Reviewed-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Signed-off-by: Dillon Varone Dillon.Varone@amd.com Signed-off-by: Wayne Lin wayne.lin@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../drm/amd/display/dmub/src/dmub_dcn401.c | 47 ++++++++++++------- .../drm/amd/display/dmub/src/dmub_dcn401.h | 3 +- 2 files changed, 32 insertions(+), 18 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.c index 39a8cb6d7523c..e1c4fe1c6e3ee 100644 --- a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.c +++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.c @@ -63,8 +63,10 @@ static inline void dmub_dcn401_translate_addr(const union dmub_addr *addr_in, void dmub_dcn401_reset(struct dmub_srv *dmub) { union dmub_gpint_data_register cmd; - const uint32_t timeout = 30; - uint32_t in_reset, scratch, i; + const uint32_t timeout_us = 1 * 1000 * 1000; //1s + const uint32_t poll_delay_us = 1; //1us + uint32_t i = 0; + uint32_t in_reset, scratch, pwait_mode;
REG_GET(DMCUB_CNTL2, DMCUB_SOFT_RESET, &in_reset);
@@ -75,32 +77,35 @@ void dmub_dcn401_reset(struct dmub_srv *dmub)
dmub->hw_funcs.set_gpint(dmub, cmd);
- /** - * Timeout covers both the ACK and the wait - * for remaining work to finish. - * - * This is mostly bound by the PHY disable sequence. - * Each register check will be greater than 1us, so - * don't bother using udelay. - */ - - for (i = 0; i < timeout; ++i) { + for (i = 0; i < timeout_us; i++) { if (dmub->hw_funcs.is_gpint_acked(dmub, cmd)) break; + + udelay(poll_delay_us); }
- for (i = 0; i < timeout; ++i) { + for (; i < timeout_us; i++) { scratch = dmub->hw_funcs.get_gpint_response(dmub); if (scratch == DMUB_GPINT__STOP_FW_RESPONSE) break; + + udelay(poll_delay_us); }
- /* Force reset in case we timed out, DMCUB is likely hung. */ + for (; i < timeout_us; i++) { + REG_GET(DMCUB_CNTL, DMCUB_PWAIT_MODE_STATUS, &pwait_mode); + if (pwait_mode & (1 << 0)) + break; + + udelay(poll_delay_us); + } + } + + if (i >= timeout_us) { + /* timeout should never occur */ + BREAK_TO_DEBUGGER(); }
- REG_UPDATE(DMCUB_CNTL2, DMCUB_SOFT_RESET, 1); - REG_UPDATE(DMCUB_CNTL, DMCUB_ENABLE, 0); - REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 1); REG_WRITE(DMCUB_INBOX1_RPTR, 0); REG_WRITE(DMCUB_INBOX1_WPTR, 0); REG_WRITE(DMCUB_OUTBOX1_RPTR, 0); @@ -131,7 +136,10 @@ void dmub_dcn401_backdoor_load(struct dmub_srv *dmub,
dmub_dcn401_get_fb_base_offset(dmub, &fb_base, &fb_offset);
+ /* reset and disable DMCUB and MMHUBBUB DMUIF */ REG_UPDATE(DMCUB_SEC_CNTL, DMCUB_SEC_RESET, 1); + REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 1); + REG_UPDATE(DMCUB_CNTL, DMCUB_ENABLE, 0);
dmub_dcn401_translate_addr(&cw0->offset, fb_base, fb_offset, &offset);
@@ -151,6 +159,7 @@ void dmub_dcn401_backdoor_load(struct dmub_srv *dmub, DMCUB_REGION3_CW1_TOP_ADDRESS, cw1->region.top, DMCUB_REGION3_CW1_ENABLE, 1);
+ /* release DMCUB reset only to prevent premature execution */ REG_UPDATE_2(DMCUB_SEC_CNTL, DMCUB_SEC_RESET, 0, DMCUB_MEM_UNIT_ID, 0x20); } @@ -161,7 +170,10 @@ void dmub_dcn401_backdoor_load_zfb_mode(struct dmub_srv *dmub, { union dmub_addr offset;
+ /* reset and disable DMCUB and MMHUBBUB DMUIF */ REG_UPDATE(DMCUB_SEC_CNTL, DMCUB_SEC_RESET, 1); + REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 1); + REG_UPDATE(DMCUB_CNTL, DMCUB_ENABLE, 0);
offset = cw0->offset;
@@ -181,6 +193,7 @@ void dmub_dcn401_backdoor_load_zfb_mode(struct dmub_srv *dmub, DMCUB_REGION3_CW1_TOP_ADDRESS, cw1->region.top, DMCUB_REGION3_CW1_ENABLE, 1);
+ /* release DMCUB reset only to prevent premature execution */ REG_UPDATE_2(DMCUB_SEC_CNTL, DMCUB_SEC_RESET, 0, DMCUB_MEM_UNIT_ID, 0x20); } diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.h b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.h index 4c8843b796950..31f95b27e227d 100644 --- a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.h +++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn401.h @@ -169,7 +169,8 @@ struct dmub_srv; DMUB_SF(HOST_INTERRUPT_CSR, HOST_REG_INBOX0_RSP_INT_EN) \ DMUB_SF(HOST_INTERRUPT_CSR, HOST_REG_OUTBOX0_RDY_INT_ACK) \ DMUB_SF(HOST_INTERRUPT_CSR, HOST_REG_OUTBOX0_RDY_INT_STAT) \ - DMUB_SF(HOST_INTERRUPT_CSR, HOST_REG_OUTBOX0_RDY_INT_EN) + DMUB_SF(HOST_INTERRUPT_CSR, HOST_REG_OUTBOX0_RDY_INT_EN) \ + DMUB_SF(DMCUB_CNTL, DMCUB_PWAIT_MODE_STATUS)
struct dmub_srv_dcn401_reg_offset { #define DMUB_SR(reg) uint32_t reg;