[PATCH v5] remoteproc: mediatek: Fix side effect of mt8195 sram power on

Tinghan Shen tinghan.shen at mediatek.com
Sun Mar 20 23:02:26 PDT 2022


On Fri, 2022-03-18 at 10:41 -0600, Mathieu Poirier wrote:
> On Fri, Mar 18, 2022 at 07:42:00PM +0800, Tinghan Shen wrote:
> > 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.
> > 
> > Fixes: 79111df414fc ("remoteproc: mediatek: Support mt8195 scp")
> > Signed-off-by: Tinghan Shen <tinghan.shen at mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
> > Reviewed-by: Matthias Brugger <matthias.bgg at gmail.com>
> > 
> > ---
> > v5: rebased on rproc-next
> > v4: add Fixes and Reviewed-by tags
> > v3: fix build error
> > v2: apply comments about macro definition and function calls
> > ---
> >  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 71ce4977cb0b..ea6fa1100a00 100644
> > --- a/drivers/remoteproc/mtk_common.h
> > +++ b/drivers/remoteproc/mtk_common.h
> > @@ -54,6 +54,8 @@
> >  #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 38609153bf64..068edf21ea51 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 mt8186_scp_before_load(struct mtk_scp *scp)
> > @@ -412,11 +412,32 @@ 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_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);
> > @@ -572,11 +593,25 @@ 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_RSI_BITS);
> > +	scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> >  
> >  	/* Disable SCP watchdog */
> >  	writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
> > @@ -922,11 +957,11 @@ 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,
> 
> 
>   GEN     Makefile
>   UPD     include/config/kernel.release
>   UPD     include/generated/utsrelease.h
>   CALL    /home/mpoirier/work/remoteproc/kernel-review/scripts/atomic/check-atomics.sh
>   CALL    /home/mpoirier/work/remoteproc/kernel-review/scripts/checksyscalls.sh
>   CHK     include/generated/compile.h
>   CC      init/version.o
>   AR      init/built-in.a
>   CC      kernel/sys.o
>   CC      net/ethtool/ioctl.o
>   CC      kernel/module.o
>   CC      kernel/trace/trace.o
>   CC      drivers/base/firmware_loader/main.o
>   CC      drivers/base/firmware_loader/builtin/main.o
>   AR      net/ethtool/built-in.a
>   AR      drivers/base/firmware_loader/builtin/built-in.a
>   AR      net/built-in.a
>   AR      drivers/base/firmware_loader/built-in.a
>   AR      drivers/base/built-in.a
>   CC      drivers/remoteproc/mtk_scp.o
>   CC      drivers/remoteproc/mtk_scp_ipi.o
>   CC      drivers/ras/ras.o
>   CC      drivers/remoteproc/stm32_rproc.o
>   CC      drivers/nvmem/core.o
>   AR      kernel/trace/built-in.a
>   AR      kernel/built-in.a
> /home/mpoirier/work/remoteproc/kernel-review/drivers/remoteproc/mtk_scp.c: In function
> ‘mt8186_scp_before_load’:
> /home/mpoirier/work/remoteproc/kernel-review/drivers/remoteproc/mtk_scp.c:396:2: error: implicit
> declaration of function ‘mt8192_power_on_sram’ [-Werror=implicit-function-declaration]
>   396 |  mt8192_power_on_sram(scp->reg_base + MT8183_SCP_SRAM_PDN);
>       |  ^~~~~~~~~~~~~~~~~~~~
> ...
> 
> No need to send me another revision right away - I won't apply your code for
> this merge window.

Hi Mathieu,


I'm sorry. I'll correct this at next version.



Best regards,
TingHan

> 
> > -- 
> > 2.18.0
> > 




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