Re: [Intel-gfx] [PATCH v2 01/11] drm/dp_mst: Store the MST PBN divider value in fixed point format

[Imre Deak <imre.deak@intel.com>]

On Thu, Nov 16, 2023 at 03:18:31PM +0200, Imre Deak wrote:
[...]
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> index ed784cf27d396..63024393b516e 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> @@ -31,6 +31,7 @@
>  #include <drm/drm_probe_helper.h>
>  #include <drm/amdgpu_drm.h>
>  #include <drm/drm_edid.h>
> +#include <drm/drm_fixed.h>
>  
>  #include "dm_services.h"
>  #include "amdgpu.h"
> @@ -210,7 +211,7 @@ static void dm_helpers_construct_old_payload(
>  			struct drm_dp_mst_atomic_payload *old_payload)
>  {
>  	struct drm_dp_mst_atomic_payload *pos;
> -	int pbn_per_slot = mst_state->pbn_div;
> +	int pbn_per_slot = dfixed_trunc(mst_state->pbn_div);
>  	u8 next_payload_vc_start = mgr->next_start_slot;
>  	u8 payload_vc_start = new_payload->vc_start_slot;
>  	u8 allocated_time_slots;

I'm planning to merge this patchset today via drm-intel-next and for
that I'll need to rebase the above change to:

@@ -205,13 +206,14 @@ void dm_helpers_dp_update_branch_info(

 static void dm_helpers_construct_old_payload(
                        struct dc_link *link,
-                       int pbn_per_slot,
+                       fixed20_12 pbn_per_slot_fp,
                        struct drm_dp_mst_atomic_payload *new_payload,
                        struct drm_dp_mst_atomic_payload *old_payload)
 {
        struct link_mst_stream_allocation_table current_link_table =
                                                                        link->mst_stream_alloc_table;
        struct link_mst_stream_allocation *dc_alloc;
+       int pbn_per_slot = dfixed_trunc(pbn_per_slot_fp);
        int i;

        *old_payload = *new_payload;

and then apply the original changes in the patch above while merging
drm-intel-next to drm-tip. This is required due to

commit 9031e0013f819c ("drm/amd/display: Fix mst hub unplug warning")

being only in drm-misc-next, but not yet in drm-intel-next.

Let me know if you have a concern with this.

--Imre