From: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com
[ Upstream commit ab14c99c035da7156a3b66fa171171295bc4b89a ]
The mdp_ipi_comm structure defines a command that is either PROCESS (start processing) or DEINIT (destroy instance); we are using this one to send PROCESS or DEINIT commands from Linux to an MDP instance through a VPU write but, while the first wants us to stay 4-bytes aligned, the VPU instead requires an 8-bytes data alignment.
Keeping in mind that these commands are executed immediately after sending them (hence not chained with others before the VPU/MDP "actually" start executing), it is fine to simply add a padding of 4 bytes to this structure: this keeps the same performance as before, as we're still stack-allocating it, while avoiding hackery inside of mtk-vpu to ensure alignment bringing a definitely bigger performance impact.
Fixes: c8eb2d7e8202 ("[media] media: Add Mediatek MDP Driver") Signed-off-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Reviewed-by: Houlong Wei houlong.wei@mediatek.com Reviewed-by: Irui Wang irui.wang@mediatek.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/platform/mtk-mdp/mtk_mdp_ipi.h | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_ipi.h b/drivers/media/platform/mtk-mdp/mtk_mdp_ipi.h index 2cb8cecb3077..b810c96695c8 100644 --- a/drivers/media/platform/mtk-mdp/mtk_mdp_ipi.h +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_ipi.h @@ -40,12 +40,14 @@ struct mdp_ipi_init { * @ipi_id : IPI_MDP * @ap_inst : AP mtk_mdp_vpu address * @vpu_inst_addr : VPU MDP instance address + * @padding : Alignment padding */ struct mdp_ipi_comm { uint32_t msg_id; uint32_t ipi_id; uint64_t ap_inst; uint32_t vpu_inst_addr; + uint32_t padding; };
/**