| Message ID | 20210107023020.3224002-1-tzungbi@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] remoteproc/mediatek: enable MPU for all memory regions in MT8192 SCP | expand |
On Thu, Jan 07, 2021 at 10:30:20AM +0800, Tzung-Bi Shih wrote: > The register MT8192_CORE0_MEM_ATT_PREDEF contains attributes for each > memory region. It defines whether a memory region can be managed by MPU > or not. > > In the past, due to the default settings in the register, MT8192 SCP > works luckily. After enabling L1TCM, SCP starts to access memory region > that is not included in the default settings. As a result, SCP hangs. > > Enables MPU for all memory regions in MT8192 SCP. > > Note that the register is read only once when SCP resets. Thus, it must > be set from kernel side. Much better - now I understand what is going on. Based on the description of the problem please add a "Fixes" tag and CC stable. I also suggest you bundle this patch with your other patchset [1] once you have make the modifications for devm_platform_ioremap_resource_byname(). Thanks, Mathieu [1]. https://patchwork.kernel.org/project/linux-remoteproc/list/?series=401287 > > Signed-off-by: Tzung-Bi Shih <tzungbi@google.com> > --- > Changes from v1[1]: > - Adds more details in commit message. > > [1]: https://patchwork.kernel.org/project/linux-remoteproc/patch/20201214051047.859110-1-tzungbi@google.com/ > > drivers/remoteproc/mtk_common.h | 1 + > drivers/remoteproc/mtk_scp.c | 3 +++ > 2 files changed, 4 insertions(+) > > diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h > index 94bc54b224ee..5f7cd2336cef 100644 > --- a/drivers/remoteproc/mtk_common.h > +++ b/drivers/remoteproc/mtk_common.h > @@ -47,6 +47,7 @@ > > #define MT8192_CORE0_SW_RSTN_CLR 0x10000 > #define MT8192_CORE0_SW_RSTN_SET 0x10004 > +#define MT8192_CORE0_MEM_ATT_PREDEF 0x10008 > #define MT8192_CORE0_WDT_CFG 0x10034 > > #define SCP_FW_VER_LEN 32 > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c > index f025aba67abc..130c0b9511df 100644 > --- a/drivers/remoteproc/mtk_scp.c > +++ b/drivers/remoteproc/mtk_scp.c > @@ -369,6 +369,9 @@ static int mt8192_scp_before_load(struct mtk_scp *scp) > mt8192_power_on_sram(scp->reg_base + MT8192_L1TCM_SRAM_PDN); > mt8192_power_on_sram(scp->reg_base + MT8192_CPU0_SRAM_PD); > > + /* enable MPU for all memory regions */ > + writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF); > + > return 0; > } > > -- > 2.29.2.729.g45daf8777d-goog >
diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h index 94bc54b224ee..5f7cd2336cef 100644 --- a/drivers/remoteproc/mtk_common.h +++ b/drivers/remoteproc/mtk_common.h @@ -47,6 +47,7 @@ #define MT8192_CORE0_SW_RSTN_CLR 0x10000 #define MT8192_CORE0_SW_RSTN_SET 0x10004 +#define MT8192_CORE0_MEM_ATT_PREDEF 0x10008 #define MT8192_CORE0_WDT_CFG 0x10034 #define SCP_FW_VER_LEN 32 diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c index f025aba67abc..130c0b9511df 100644 --- a/drivers/remoteproc/mtk_scp.c +++ b/drivers/remoteproc/mtk_scp.c @@ -369,6 +369,9 @@ static int mt8192_scp_before_load(struct mtk_scp *scp) mt8192_power_on_sram(scp->reg_base + MT8192_L1TCM_SRAM_PDN); mt8192_power_on_sram(scp->reg_base + MT8192_CPU0_SRAM_PD); + /* enable MPU for all memory regions */ + writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF); + return 0; }
The register MT8192_CORE0_MEM_ATT_PREDEF contains attributes for each memory region. It defines whether a memory region can be managed by MPU or not. In the past, due to the default settings in the register, MT8192 SCP works luckily. After enabling L1TCM, SCP starts to access memory region that is not included in the default settings. As a result, SCP hangs. Enables MPU for all memory regions in MT8192 SCP. Note that the register is read only once when SCP resets. Thus, it must be set from kernel side. Signed-off-by: Tzung-Bi Shih <tzungbi@google.com> --- Changes from v1[1]: - Adds more details in commit message. [1]: https://patchwork.kernel.org/project/linux-remoteproc/patch/20201214051047.859110-1-tzungbi@google.com/ drivers/remoteproc/mtk_common.h | 1 + drivers/remoteproc/mtk_scp.c | 3 +++ 2 files changed, 4 insertions(+)