[PATCH] soc: mediatek: Fix random hang up issue while kernel init

James Liao
2015-09-25T06:31:57Z

In kernel late init, it turns off all unused clocks, which
needs to access subsystem registers such as VENC and VENC_LT.

Accessing MT8173 VENC registers needs two top clocks, mm_sel and
venc_sel. Accessing VENC_LT registers needs mm_sel and venclt_sel.
So we need to keep these clocks on before accessing their registers.

This patch keeps venc_sel / venclt_sel clock on when
VENC / VENC_LT's power is on, to prevent system hang up while
accessing its registeres.

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
---

This patch is based on v4.3-rc2, to fix system hanging up issue
while disabling unused clocks.

arch/arm64/boot/dts/mediatek/mt8173.dtsi | 6 ++-
drivers/soc/mediatek/mtk-scpsys.c | 67 +++++++++++++++++++++-----------
2 files changed, 48 insertions(+), 25 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8173.dtsi b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
index d18ee42..188917f 100644
--- a/arch/arm64/boot/dts/mediatek/mt8173.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
@@ -227,8 +227,10 @@
#power-domain-cells = <1>;
reg = <0 0x10006000 0 0x1000>;
clocks = <&clk26m>,
- <&topckgen CLK_TOP_MM_SEL>;
- clock-names = "mfg", "mm";
+ <&topckgen CLK_TOP_MM_SEL>,
+ <&topckgen CLK_TOP_VENC_SEL>,
+ <&topckgen CLK_TOP_VENC_LT_SEL>;
+ clock-names = "mfg", "mm", "venc", "venc_lt";
infracfg = <&infracfg>;
};

diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index 164a7d8..06032ba 100644
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -54,12 +54,16 @@
#define PWR_STATUS_USB BIT(25)

enum clk_id {
+ MT8173_CLK_NONE,
MT8173_CLK_MM,
MT8173_CLK_MFG,
- MT8173_CLK_NONE,
- MT8173_CLK_MAX = MT8173_CLK_NONE,
+ MT8173_CLK_VENC,
+ MT8173_CLK_VENC_LT,
+ MT8173_CLK_MAX,
};

+#define MAX_CLKS 2
+
struct scp_domain_data {
const char *name;
u32 sta_mask;
@@ -67,7 +71,7 @@ struct scp_domain_data {
u32 sram_pdn_bits;
u32 sram_pdn_ack_bits;
u32 bus_prot_mask;
- enum clk_id clk_id;
+ enum clk_id clk_id[MAX_CLKS];
};

static const struct scp_domain_data scp_domain_data[] __initconst = {
@@ -77,7 +81,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_VDE_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(12, 12),
- .clk_id = MT8173_CLK_MM,
+ .clk_id = {MT8173_CLK_MM},
},
[MT8173_POWER_DOMAIN_VENC] = {
.name = "venc",
@@ -85,7 +89,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_VEN_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(15, 12),
- .clk_id = MT8173_CLK_MM,
+ .clk_id = {MT8173_CLK_MM, MT8173_CLK_VENC},
},
[MT8173_POWER_DOMAIN_ISP] = {
.name = "isp",
@@ -93,7 +97,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_ISP_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(13, 12),
- .clk_id = MT8173_CLK_MM,
+ .clk_id = {MT8173_CLK_MM},
},
[MT8173_POWER_DOMAIN_MM] = {
.name = "mm",
@@ -101,7 +105,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_DIS_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(12, 12),
- .clk_id = MT8173_CLK_MM,
+ .clk_id = {MT8173_CLK_MM},
.bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MM_M0 |
MT8173_TOP_AXI_PROT_EN_MM_M1,
},
@@ -111,7 +115,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_VEN2_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(15, 12),
- .clk_id = MT8173_CLK_MM,
+ .clk_id = {MT8173_CLK_MM, MT8173_CLK_VENC_LT},
},
[MT8173_POWER_DOMAIN_AUDIO] = {
.name = "audio",
@@ -119,7 +123,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_AUDIO_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(15, 12),
- .clk_id = MT8173_CLK_NONE,
+ .clk_id = {MT8173_CLK_NONE},
},
[MT8173_POWER_DOMAIN_USB] = {
.name = "usb",
@@ -127,7 +131,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_USB_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(15, 12),
- .clk_id = MT8173_CLK_NONE,
+ .clk_id = {MT8173_CLK_NONE},
},
[MT8173_POWER_DOMAIN_MFG_ASYNC] = {
.name = "mfg_async",
@@ -135,7 +139,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_MFG_ASYNC_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = 0,
- .clk_id = MT8173_CLK_MFG,
+ .clk_id = {MT8173_CLK_MFG},
},
[MT8173_POWER_DOMAIN_MFG_2D] = {
.name = "mfg_2d",
@@ -143,7 +147,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_MFG_2D_PWR_CON,
.sram_pdn_bits = GENMASK(11, 8),
.sram_pdn_ack_bits = GENMASK(13, 12),
- .clk_id = MT8173_CLK_NONE,
+ .clk_id = {MT8173_CLK_NONE},
},
[MT8173_POWER_DOMAIN_MFG] = {
.name = "mfg",
@@ -151,7 +155,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
.ctl_offs = SPM_MFG_PWR_CON,
.sram_pdn_bits = GENMASK(13, 8),
.sram_pdn_ack_bits = GENMASK(21, 16),
- .clk_id = MT8173_CLK_NONE,
+ .clk_id = {MT8173_CLK_NONE},
.bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MFG_S |
MT8173_TOP_AXI_PROT_EN_MFG_M0 |
MT8173_TOP_AXI_PROT_EN_MFG_M1 |
@@ -166,7 +170,7 @@ struct scp;
struct scp_domain {
struct generic_pm_domain genpd;
struct scp *scp;
- struct clk *clk;
+ struct clk *clk[MAX_CLKS];
u32 sta_mask;
void __iomem *ctl_addr;
u32 sram_pdn_bits;
@@ -212,11 +216,16 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
u32 sram_pdn_ack = scpd->sram_pdn_ack_bits;
u32 val;
int ret;
+ int i;
+
+ for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++) {
+ ret = clk_prepare_enable(scpd->clk[i]);
+ if (ret) {
+ for (--i; i >= 0; i--)
+ clk_disable_unprepare(scpd->clk[i]);

- if (scpd->clk) {
- ret = clk_prepare_enable(scpd->clk);
- if (ret)
goto err_clk;
+ }
}

val = readl(ctl_addr);
@@ -282,7 +291,10 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
return 0;

err_pwr_ack:
- clk_disable_unprepare(scpd->clk);
+ for (i = MAX_CLKS - 1; i >= 0; i--) {
+ if (scpd->clk[i])
+ clk_disable_unprepare(scpd->clk[i]);
+ }
err_clk:
dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);

@@ -299,6 +311,7 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
u32 pdn_ack = scpd->sram_pdn_ack_bits;
u32 val;
int ret;
+ int i;

if (scpd->bus_prot_mask) {
ret = mtk_infracfg_set_bus_protection(scp->infracfg,
@@ -360,8 +373,8 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
expired = true;
}

- if (scpd->clk)
- clk_disable_unprepare(scpd->clk);
+ for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++)
+ clk_disable_unprepare(scpd->clk[i]);

return 0;

@@ -375,7 +388,7 @@ static int __init scpsys_probe(struct platform_device *pdev)
{
struct genpd_onecell_data *pd_data;
struct resource *res;
- int i, ret;
+ int i, j, ret;
struct scp *scp;
struct clk *clk[MT8173_CLK_MAX];

@@ -405,6 +418,14 @@ static int __init scpsys_probe(struct platform_device *pdev)
if (IS_ERR(clk[MT8173_CLK_MFG]))
return PTR_ERR(clk[MT8173_CLK_MFG]);

+ clk[MT8173_CLK_VENC] = devm_clk_get(&pdev->dev, "venc");
+ if (IS_ERR(clk[MT8173_CLK_VENC]))
+ return PTR_ERR(clk[MT8173_CLK_VENC]);
+
+ clk[MT8173_CLK_VENC_LT] = devm_clk_get(&pdev->dev, "venc_lt");
+ if (IS_ERR(clk[MT8173_CLK_VENC_LT]))
+ return PTR_ERR(clk[MT8173_CLK_VENC_LT]);
+
scp->infracfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
"infracfg");
if (IS_ERR(scp->infracfg)) {
@@ -428,8 +449,8 @@ static int __init scpsys_probe(struct platform_device *pdev)
scpd->sram_pdn_bits = data->sram_pdn_bits;
scpd->sram_pdn_ack_bits = data->sram_pdn_ack_bits;
scpd->bus_prot_mask = data->bus_prot_mask;
- if (data->clk_id != MT8173_CLK_NONE)
- scpd->clk = clk[data->clk_id];
+ for (j = 0; j < MAX_CLKS && data->clk_id[j]; j++)
+ scpd->clk[j] = clk[data->clk_id[j]];

genpd->name = data->name;
genpd->power_off = scpsys_power_off;
--
1.9.1