Re: [PATCH v2] remoteproc: mediatek: fix side effect of mt8195 sram power on

AngeloGioacchino Del Regno
2022-03-11T13:05:34Z

Il 11/03/22 13:30, Tinghan Shen ha scritto:
> The definition of L1TCM_SRAM_PDN bits on mt8195 is different to mt8192.
>
> L1TCM_SRAM_PDN bits[3:0] control the power of mt8195 L1TCM SRAM.
>
> L1TCM_SRAM_PDN bits[7:4] control the access path to EMI for SCP.
> These bits have to be powered on to allow EMI access for SCP.
>
> Bits[7:4] also affect audio DSP because audio DSP and SCP are
> placed on the same hardware bus. If SCP cannot access EMI, audio DSP is
> blocked too.
>
> L1TCM_SRAM_PDN bits[31:8] are not used.
>
> This fix removes modification of bits[7:4] when power on/off mt8195 SCP
> L1TCM. It's because the modification introduces a short period of time
> blocking audio DSP to access EMI. This was not a problem until we have
> to load both SCP module and audio DSP module. audio DSP needs to access
> EMI because it has source/data on DRAM. Audio DSP will have unexpected
> behavior when it accesses EMI and the SCP driver blocks the EMI path at
> the same time.
>
> Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
> ---
> drivers/remoteproc/mtk_common.h | 2 +
> drivers/remoteproc/mtk_scp.c | 67 +++++++++++++++++++++++++--------
> 2 files changed, 53 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
> index 5ff3867c72f3..ff954a06637c 100644
> --- a/drivers/remoteproc/mtk_common.h
> +++ b/drivers/remoteproc/mtk_common.h
> @@ -51,6 +51,8 @@
> #define MT8192_CORE0_WDT_IRQ 0x10030
> #define MT8192_CORE0_WDT_CFG 0x10034
>
> +#define MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS GENMASK(7, 4)
> +
> #define SCP_FW_VER_LEN 32
> #define SCP_SHARE_BUFFER_SIZE 288
>
> diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> index dcddb33e9997..086cf8263f6c 100644
> --- a/drivers/remoteproc/mtk_scp.c
> +++ b/drivers/remoteproc/mtk_scp.c
> @@ -365,22 +365,22 @@ static int mt8183_scp_before_load(struct mtk_scp *scp)
> return 0;
> }
>
> -static void mt8192_power_on_sram(void __iomem *addr)
> +static void scp_sram_power_on(void __iomem *addr, u32 reserved_mask)
> {
> int i;
>
> for (i = 31; i >= 0; i--)
> - writel(GENMASK(i, 0), addr);
> + writel(GENMASK(i, 0) & ~reserved_mask, addr);
> writel(0, addr);
> }
>
> -static void mt8192_power_off_sram(void __iomem *addr)
> +static void scp_sram_power_off(void __iomem *addr, u32 reserved_mask)
> {
> int i;
>
> writel(0, addr);
> for (i = 0; i < 32; i++)
> - writel(GENMASK(i, 0), addr);
> + writel(GENMASK(i, 0) & ~reserved_mask, addr);
> }
>
> static int mt8192_scp_before_load(struct mtk_scp *scp)
> @@ -391,11 +391,32 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
> writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
>
> /* enable SRAM clock */
> - mt8192_power_on_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_0);
> - mt8192_power_on_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_1);
> - mt8192_power_on_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_2);
> - mt8192_power_on_sram(scp->reg_base + MT8192_L1TCM_SRAM_PDN);
> - mt8192_power_on_sram(scp->reg_base + MT8192_CPU0_SRAM_PD);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> +
> + /* enable MPU for all memory regions */
> + writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF);
> +
> + return 0;
> +}
> +
> +static int mt8195_scp_before_load(struct mtk_scp *scp)
> +{
> + /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> + writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> +
> + writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
> +
> + /* enable SRAM clock */
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> + MT8195_L1TCM_SRAM_PDN_RESERVED_BITS);

This is supposed to be MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS.

> + scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
>
> /* enable MPU for all memory regions */
> writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF);
> @@ -551,11 +572,25 @@ static void mt8183_scp_stop(struct mtk_scp *scp)
> static void mt8192_scp_stop(struct mtk_scp *scp)
> {
> /* Disable SRAM clock */
> - mt8192_power_off_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_0);
> - mt8192_power_off_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_1);
> - mt8192_power_off_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_2);
> - mt8192_power_off_sram(scp->reg_base + MT8192_L1TCM_SRAM_PDN);
> - mt8192_power_off_sram(scp->reg_base + MT8192_CPU0_SRAM_PD);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> +
> + /* Disable SCP watchdog */
> + writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
> +}
> +
> +static void mt8195_scp_stop(struct mtk_scp *scp)
> +{
> + /* Disable SRAM clock */
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> + MT8195_L1TCM_SRAM_PDN_RESERVED_BITS);

same here.

> + scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
>
> /* Disable SCP watchdog */
> writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
> @@ -888,11 +923,11 @@ static const struct mtk_scp_of_data mt8192_of_data = {
>
> static const struct mtk_scp_of_data mt8195_of_data = {
> .scp_clk_get = mt8195_scp_clk_get,
> - .scp_before_load = mt8192_scp_before_load,
> + .scp_before_load = mt8195_scp_before_load,
> .scp_irq_handler = mt8192_scp_irq_handler,
> .scp_reset_assert = mt8192_scp_reset_assert,
> .scp_reset_deassert = mt8192_scp_reset_deassert,
> - .scp_stop = mt8192_scp_stop,
> + .scp_stop = mt8195_scp_stop,
> .scp_da_to_va = mt8192_scp_da_to_va,
> .host_to_scp_reg = MT8192_GIPC_IN_SET,
> .host_to_scp_int_bit = MT8192_HOST_IPC_INT_BIT,