diff options
| author | Julian Parkin <julian.parkin@amd.com> | 2019-06-13 12:49:37 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-07-18 14:17:19 -0500 |
| commit | ca6f188cdf80de09b92174cf5fb2716021264222 (patch) | |
| tree | 31039c7f9b03a414084296558ce57ab5288f3bef /drivers/gpu/drm/amd/display/dc/dcn20 | |
| parent | dd5d9348da02dd83dbb235e55aa0acb3f48ccc95 (diff) | |
drm/amd/display: Poll for GPUVM context ready (v2)
[Why]
Hardware docs state that we must wait until the GPUVM context is ready
after programming it.
[How]
Poll until the valid bit of PAGE_TABLE_BASE_ADDR_LO32 is set to 1 after
programming it.
v2: fix include for udelay (Alex)
Signed-off-by: Julian Parkin <julian.parkin@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/dcn20')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c index 27679ef6ebe8..96c263223315 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_vmid.c @@ -23,6 +23,8 @@ * */ +#include <linux/delay.h> + #include "dcn20_vmid.h" #include "reg_helper.h" @@ -36,6 +38,38 @@ #define FN(reg_name, field_name) \ vmid->shifts->field_name, vmid->masks->field_name +static void dcn20_wait_for_vmid_ready(struct dcn20_vmid *vmid) +{ + /* According the hardware spec, we need to poll for the lowest + * bit of PAGE_TABLE_BASE_ADDR_LO32 = 1 any time a GPUVM + * context is updated. We can't use REG_WAIT here since we + * don't have a seperate field to wait on. + * + * TODO: Confirm timeout / poll interval with hardware team + */ + + int max_times = 10000; + int delay_us = 5; + int i; + + for (i = 0; i < max_times; ++i) { + uint32_t entry_lo32; + + REG_GET(PAGE_TABLE_BASE_ADDR_LO32, + VM_CONTEXT0_PAGE_DIRECTORY_ENTRY_LO32, + &entry_lo32); + + if (entry_lo32 & 0x1) + return; + + udelay(delay_us); + } + + /* VM setup timed out */ + DC_LOG_WARNING("Timeout while waiting for GPUVM context update\n"); + ASSERT(0); +} + void dcn20_vmid_setup(struct dcn20_vmid *vmid, const struct dcn_vmid_page_table_config *config) { REG_SET(PAGE_TABLE_START_ADDR_HI32, 0, @@ -54,6 +88,9 @@ void dcn20_vmid_setup(struct dcn20_vmid *vmid, const struct dcn_vmid_page_table_ REG_SET(PAGE_TABLE_BASE_ADDR_HI32, 0, VM_CONTEXT0_PAGE_DIRECTORY_ENTRY_HI32, (config->page_table_base_addr >> 32) & 0xFFFFFFFF); + /* Note: per hardware spec PAGE_TABLE_BASE_ADDR_LO32 must be programmed last in sequence */ REG_SET(PAGE_TABLE_BASE_ADDR_LO32, 0, VM_CONTEXT0_PAGE_DIRECTORY_ENTRY_LO32, config->page_table_base_addr & 0xFFFFFFFF); + + dcn20_wait_for_vmid_ready(vmid); } |