Hi Ivaylo,
it took a while until I found time to test newer kernels (mainline + Letux additions)
on the OMAP5 Pyra but unfortunately I did not get screen display for v6.1. Even worse,
the console was flooded by
[ 39.419846] WARNING: CPU: 0 PID: 3673 at drivers/bus/omap_l3_noc.c:139 l3_interrupt_handler+0x23c/0x330
[ 39.429914] 44000000.l3-noc:L3 Custom Error: MASTER MPU TARGET GPMC (Idle): Data Access in Supervisor mode during Functional access
...
making the system unuseable.
After doing some manual bisect by installing different kernel versions on the boot SD card,
I was able to identify that it crept in between v5.18 and v5.19-rc1. A git bisect on this
range (adding Letux patches on top of each bisect base) did reveal this patch as the first bad one.
After reverting it seems as if I can use any v5.19 .. v6.1-rc2 kernel without issues.
Now I wonder why this patch breaks my system?
BR and thanks,
Nikolaus
> Am 19.01.2022 um 11:23 schrieb Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>:
>
> On devices with DMM, all allocations are done through either DMM or TILER.
> DMM/TILER being a limited resource means that such allocations will start
> to fail before actual free memory is exhausted. What is even worse is that
> with time DMM/TILER space gets fragmented to the point that even if we have
> enough free DMM/TILER space and free memory, allocation fails because there
> is no big enough free block in DMM/TILER space.
>
> Such failures can be easily observed with OMAP xorg DDX, for example -
> starting few GUI applications (so buffers for their windows are allocated)
> and then rotating landscape<->portrait while closing and opening new
> windows soon results in allocation failures.
>
> Fix that by mapping buffers through DMM/TILER only when really needed,
> like, for scanout buffers.
>
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
> ---
> drivers/gpu/drm/omapdrm/omap_gem.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
> index 41c1a6d..cf57179 100644
> --- a/drivers/gpu/drm/omapdrm/omap_gem.c
> +++ b/drivers/gpu/drm/omapdrm/omap_gem.c
> @@ -821,10 +821,12 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr)
> if (ret)
> goto fail;
>
> - if (priv->has_dmm) {
> - ret = omap_gem_pin_tiler(obj);
> - if (ret)
> - goto fail;
> + if (omap_obj->flags & OMAP_BO_SCANOUT) {
> + if (priv->has_dmm) {
> + ret = omap_gem_pin_tiler(obj);
> + if (ret)
> + goto fail;
> + }
> }
> } else {
> refcount_inc(&omap_obj->pin_cnt);
> @@ -861,6 +863,8 @@ static void omap_gem_unpin_locked(struct drm_gem_object *obj)
> kfree(omap_obj->sgt);
> omap_obj->sgt = NULL;
> }
> + if (!(omap_obj->flags & OMAP_BO_SCANOUT))
> + return;
> if (priv->has_dmm) {
> ret = tiler_unpin(omap_obj->block);
> if (ret) {
> --
> 1.9.1
>
