On 15 July 2016 at 08:27, Tomasz Figa <tf...@chromium.org> wrote:
> When a buffer with a GEM handle already existing in our context is
> (re-)imported from a PRIME FD, the resulting GEM handle is exactly the
> same as the original one. Since the GEM handles are not reference
> counted, we need to detect duplicate imports and reference count our
> internal buffer structs ourselves.
>
> Signed-off-by: Tomasz Figa <tf...@chromium.org>
> ---
> src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c | 30
> +++++++++++++++++------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> index 21ac0d7..c4f56cb 100644
> --- a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> +++ b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> @@ -211,7 +211,9 @@ kms_sw_displaytarget_map(struct sw_winsys *ws,
> }
>
> static struct kms_sw_displaytarget *
> -kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd)
> +kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd,
> + unsigned width, unsigned height,
> + unsigned stride)
> {
> uint32_t handle = -1;
> struct kms_sw_displaytarget * kms_sw_dt;
> @@ -222,6 +224,17 @@ kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys
> *kms_sw, int fd)
> if (ret)
> return NULL;
>
> + LIST_FOR_EACH_ENTRY(kms_sw_dt, &kms_sw->bo_list, link) {
> + if (kms_sw_dt->handle == handle) {
> + kms_sw_dt->ref_count++;
> +
> + DEBUG_PRINT("KMS-DEBUG: imported buffer %u (size %u)\n",
> + kms_sw_dt->handle, kms_sw_dt->size);
> +
> + return kms_sw_dt;
> + }
> + }
> +
> kms_sw_dt = CALLOC_STRUCT(kms_sw_displaytarget);
> if (!kms_sw_dt)
> return NULL;
> @@ -229,6 +242,9 @@ kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys
> *kms_sw, int fd)
> kms_sw_dt->ref_count = 1;
> kms_sw_dt->handle = handle;
> kms_sw_dt->size = lseek(fd, 0, SEEK_END);
> + kms_sw_dt->width = width;
> + kms_sw_dt->height = height;
> + kms_sw_dt->stride = stride;
>
> if (kms_sw_dt->size == (off_t)-1) {
> FREE(kms_sw_dt);
> @@ -274,14 +290,12 @@ kms_sw_displaytarget_from_handle(struct sw_winsys *ws,
>
> switch(whandle->type) {
> case DRM_API_HANDLE_TYPE_FD:
> - kms_sw_dt = kms_sw_displaytarget_add_from_prime(kms_sw,
> whandle->handle);
> - if (kms_sw_dt) {
> - kms_sw_dt->ref_count++;
> - kms_sw_dt->width = templ->width0;
> - kms_sw_dt->height = templ->height0;
> - kms_sw_dt->stride = whandle->stride;
> + kms_sw_dt = kms_sw_displaytarget_add_from_prime(kms_sw,
> whandle->handle,
> + templ->width0,
> + templ->height0,
> + whandle->stride);
> + if (kms_sw_dt)
> *stride = kms_sw_dt->stride;
> - }
So there's actually a couple of things here:
- kms_sw_displaytarget_add_from_prime now takes a width, height,
stride. not a bugfix but very nice imho.
- DRM_API_HANDLE_TYPE_FD were ref_counted twice upon creation - once
in kms_sw_displaytarget_add_from_prime, and a second time immediatelly
after.
- one should have checked the bo_list prior to importing the BO as prime FD.
Can we split the former (2/2) and get the other two (1/2) with CC:
mesa-stable... ?
Ideally we would have just a single
"LIST_FOR_EACH_ENTRY(...&kms_sw->bo_list...)" block in
kms_sw_displaytarget_from_handle and none in
kms_sw_displaytarget_add_from_prime.
Thanks
Emil
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