Re: [PATCH v4 6/8] soc: mediatek: Add programming flow for unsupported subsys ID hardware

AngeloGioacchino Del Regno
2025-03-04T09:41:47Z

Il 18/02/25 06:41, Jason-JH Lin ha scritto:
> To support hardware without subsys IDs on new SoCs, add a programming
> flow that checks whether the subsys ID is valid. If the subsys ID is
> invalid, the flow will call 2 alternative CMDQ APIs:
> cmdq_pkt_assign() and cmdq_pkt_write_s_value() to achieve the same
> functionality.
>
> Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
> ---
> drivers/soc/mediatek/mtk-mmsys.c | 14 +++++++++++---
> drivers/soc/mediatek/mtk-mutex.c | 11 +++++++++--
> 2 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
> index bb4639ca0b8c..ce949b863b05 100644
> --- a/drivers/soc/mediatek/mtk-mmsys.c
> +++ b/drivers/soc/mediatek/mtk-mmsys.c
> @@ -167,9 +167,17 @@ static void mtk_mmsys_update_bits(struct mtk_mmsys *mmsys, u32 offset, u32 mask,
> u32 tmp;
>
> if (mmsys->cmdq_base.size && cmdq_pkt) {
> - ret = cmdq_pkt_write_mask(cmdq_pkt, mmsys->cmdq_base.subsys,
> - mmsys->cmdq_base.offset + offset, val,
> - mask);
> + offset += mmsys->cmdq_base.offset;
> + if (mmsys->cmdq_base.subsys != CMDQ_SUBSYS_INVALID) {

You're still anyway passing the subsys to cmdq_pkt_write_mask(), right?!
Why don't you just handle this in cmdq_pkt_write_mask() then? ;-)

I can see this pattern being repeated over and over in both drm/mediatek and MDP3
drivers, and it's not necessary to duplicate this many times when you can write it
just once.

Would've also been faster for you to implement... :-D

Cheers,
Angelo

> + ret = cmdq_pkt_write_mask(cmdq_pkt, mmsys->cmdq_base.subsys,
> + offset, val, mask);
> + } else {
> + /* only MMIO access, no need to check mminfro_offset */
> + ret = cmdq_pkt_assign(cmdq_pkt, CMDQ_THR_SPR_IDX0,
> + CMDQ_ADDR_HIGH(mmsys->cmdq_base.pa_base));
> + ret |= cmdq_pkt_write_s_mask_value(cmdq_pkt, CMDQ_THR_SPR_IDX0,
> + CMDQ_ADDR_LOW(offset), val, mask);
> + }
> if (ret)
> pr_debug("CMDQ unavailable: using CPU write\n");
> else
> diff --git a/drivers/soc/mediatek/mtk-mutex.c b/drivers/soc/mediatek/mtk-mutex.c
> index 5250c1d702eb..3788b16efbf4 100644
> --- a/drivers/soc/mediatek/mtk-mutex.c
> +++ b/drivers/soc/mediatek/mtk-mutex.c
> @@ -963,6 +963,7 @@ int mtk_mutex_enable_by_cmdq(struct mtk_mutex *mutex, void *pkt)
> struct mtk_mutex_ctx *mtx = container_of(mutex, struct mtk_mutex_ctx,
> mutex[mutex->id]);
> struct cmdq_pkt *cmdq_pkt = (struct cmdq_pkt *)pkt;
> + dma_addr_t en_addr = mtx->addr + DISP_REG_MUTEX_EN(mutex->id);
>
> WARN_ON(&mtx->mutex[mutex->id] != mutex);
>
> @@ -971,8 +972,14 @@ int mtk_mutex_enable_by_cmdq(struct mtk_mutex *mutex, void *pkt)
> return -ENODEV;
> }
>
> - cmdq_pkt_write(cmdq_pkt, mtx->cmdq_reg.subsys,
> - mtx->addr + DISP_REG_MUTEX_EN(mutex->id), 1);
> + if (mtx->cmdq_reg.subsys != CMDQ_SUBSYS_INVALID) {
> + cmdq_pkt_write(cmdq_pkt, mtx->cmdq_reg.subsys, en_addr, 1);
> + } else {
> + /* only MMIO access, no need to check mminfro_offset */
> + cmdq_pkt_assign(cmdq_pkt, CMDQ_THR_SPR_IDX0, CMDQ_ADDR_HIGH(en_addr));
> + cmdq_pkt_write_s_value(cmdq_pkt, CMDQ_THR_SPR_IDX0, CMDQ_ADDR_LOW(en_addr), 1);
> + }
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(mtk_mutex_enable_by_cmdq);