[PATCH 0/4] ARM: MMC: USB: Fix clocking

Before we had critical-clock support, it was not possible to boot a kernel
without using the 'clk_ignore_unused' kernel command-line parameter.  This
was due to the existance of inter-connect clocks which weren't associated
with any physical device and thus could not be handled (think get, enable,
disable) correctly.  As a consequence the platform would catastrophically
fail when the Common Clock Framework tried to disable unused clocks.

Now we do have critical-clock support, it has identified some additional
clocks which are required for the successful functioning of some key IP.

With the introduction of critical-clock support in v4.8, our developers'
default configuration is to run with 'clk_ignore_unused' removed.  This
patch-set ensures they can achieve successful boot when a) booting from
an SD Card and when b) booting using USB->Eth adaptors for NFS booting.

Please consider this set for your respective -fixes branches for
inclusion into the v4.8-rcs.

Lee Jones (4):
  ARM: dts: STiH410: Handle interconnect clock required by EHCI/OHCI
    (USB)
  ARM: dts: STiH407-family: Provide interconnect clock for consumption
    in ST SDHCI
  dt-bindings: mmc: sdhci-st: Mention the discretionary "icn" clock
  mmc: sdhci-st: Handle interconnect clock

 Documentation/devicetree/bindings/mmc/sdhci-st.txt |  2 +-
 arch/arm/boot/dts/stih407-family.dtsi              | 10 ++++++----
 arch/arm/boot/dts/stih410.dtsi                     | 12 ++++++++----
 drivers/mmc/host/sdhci-st.c                        | 15 ++++++++++++++-
 4 files changed, 29 insertions(+), 10 deletions(-)

-- 
2.9.3

The STiH4{07,10} platform contains some interconnect clocks which are used
by various IPs.  If these clocks aren't handled correctly by ST's SDHCI
driver MMC will break and the following output can be observed:

[   13.916949] mmc0: Timeout waiting for hardware interrupt.
[   13.922349] sdhci: =========== REGISTER DUMP (mmc0)===========
[   13.928175] sdhci: Sys addr: 0x00000000 | Version:  0x00001002
[   13.933999] sdhci: Blk size: 0x00007040 | Blk cnt:  0x00000001
[   13.939825] sdhci: Argument: 0x00fffff0 | Trn mode: 0x00000013
[   13.945650] sdhci: Present:  0x1fff0206 | Host ctl: 0x00000011
[   13.951475] sdhci: Power:    0x0000000f | Blk gap:  0x00000080
[   13.957300] sdhci: Wake-up:  0x00000000 | Clock:    0x00003f07
[   13.963126] sdhci: Timeout:  0x00000004 | Int stat: 0x00000000
[   13.968952] sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
[   13.974777] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
[   13.980602] sdhci: Caps:     0x21ed3281 | Caps_1:   0x00000000
[   13.986428] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
[   13.992252] sdhci: Host ctl2: 0x00000000
[   13.996166] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x7c048200
[   14.001990] sdhci: ===========================================
[   14.009802] mmc0: Got data interrupt 0x02000000 even though no data operation was in progress.

Cc: stable at vger.kernel.org
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <redacted>
---
 arch/arm/boot/dts/stih407-family.dtsi | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
index 55ecfbe..744c5bc 100644
--- a/arch/arm/boot/dts/stih407-family.dtsi
+++ b/arch/arm/boot/dts/stih407-family.dtsi

@@ -550,8 +550,9 @@
 			interrupt-names = "mmcirq";
 			pinctrl-names = "default";
 			pinctrl-0 = <&pinctrl_mmc0>;
-			clock-names = "mmc";
-			clocks = <&clk_s_c0_flexgen CLK_MMC_0>;
+			clock-names = "mmc", "icn";
+			clocks = <&clk_s_c0_flexgen CLK_MMC_0>,
+				 <&clk_s_c0_flexgen CLK_RX_ICN_HVA>;
 			bus-width = <8>;
 		};
 

@@ -564,8 +565,9 @@
 			interrupt-names = "mmcirq";
 			pinctrl-names = "default";
 			pinctrl-0 = <&pinctrl_sd1>;
-			clock-names = "mmc";
-			clocks = <&clk_s_c0_flexgen CLK_MMC_1>;
+			clock-names = "mmc", "icn";
+			clocks = <&clk_s_c0_flexgen CLK_MMC_1>,
+				 <&clk_s_c0_flexgen CLK_RX_ICN_HVA>;
 			resets = <&softreset STIH407_MMC1_SOFTRESET>;
 			bus-width = <4>;
 		};

-- 
2.9.3

Some ST platforms contain interconnect (ICN) clocks which must be handed
correctly in order to obtain full functionality of a given IP.  In this
case, if the ICN clocks are not handled properly by the ST SDHCI driver
MMC will break and the following output can be observed:

    [   13.916949] mmc0: Timeout waiting for hardware interrupt.
    [   13.922349] sdhci: =========== REGISTER DUMP (mmc0)===========
    [   13.928175] sdhci: Sys addr: 0x00000000 | Version:  0x00001002
    [   13.933999] sdhci: Blk size: 0x00007040 | Blk cnt:  0x00000001
    [   13.939825] sdhci: Argument: 0x00fffff0 | Trn mode: 0x00000013
    [   13.945650] sdhci: Present:  0x1fff0206 | Host ctl: 0x00000011
    [   13.951475] sdhci: Power:    0x0000000f | Blk gap:  0x00000080
    [   13.957300] sdhci: Wake-up:  0x00000000 | Clock:    0x00003f07
    [   13.963126] sdhci: Timeout:  0x00000004 | Int stat: 0x00000000
    [   13.968952] sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
    [   13.974777] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
    [   13.980602] sdhci: Caps:     0x21ed3281 | Caps_1:   0x00000000
    [   13.986428] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
    [   13.992252] sdhci: Host ctl2: 0x00000000
    [   13.996166] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x7c048200
    [   14.001990] sdhci: ===========================================
    [   14.009802] mmc0: Got data interrupt 0x02000000 even though no data operation was in progress.

A decent point was raised about minimising the use of a local variable that
we 'could' do without.  I've chosen consistency over the possibility of
reducing the local variable count by 1.  Thinking that it's more important
for the code to be grouped and authoured in a similar manner/style for
greater maintainability/readability.

Cc: stable at vger.kernel.org
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <redacted>
---
 drivers/mmc/host/sdhci-st.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-st.c b/drivers/mmc/host/sdhci-st.c
index c95ba83..ed92ce7 100644
--- a/drivers/mmc/host/sdhci-st.c
+++ b/drivers/mmc/host/sdhci-st.c

@@ -28,6 +28,7 @@
 
 struct st_mmc_platform_data {
 	struct  reset_control *rstc;
+	struct  clk *icnclk;
 	void __iomem *top_ioaddr;
 };
 

@@ -353,7 +354,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
 	struct sdhci_host *host;
 	struct st_mmc_platform_data *pdata;
 	struct sdhci_pltfm_host *pltfm_host;
-	struct clk *clk;
+	struct clk *clk, *icnclk;
 	int ret = 0;
 	u16 host_version;
 	struct resource *res;

@@ -365,6 +366,11 @@ static int sdhci_st_probe(struct platform_device *pdev)
 		return PTR_ERR(clk);
 	}
 
+	/* ICN clock isn't compulsory, but use it if it's provided. */
+	icnclk = devm_clk_get(&pdev->dev, "icn");
+	if (IS_ERR(icnclk))
+		icnclk = NULL;
+
 	rstc = devm_reset_control_get(&pdev->dev, NULL);
 	if (IS_ERR(rstc))
 		rstc = NULL;

@@ -389,6 +395,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
 	}
 
 	clk_prepare_enable(clk);
+	clk_prepare_enable(icnclk);
 
 	/* Configure the FlashSS Top registers for setting eMMC TX/RX delay */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,

@@ -400,6 +407,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
 	}
 
 	pltfm_host->clk = clk;
+	pdata->icnclk = icnclk;
 
 	/* Configure the Arasan HC inside the flashSS */
 	st_mmcss_cconfig(np, host);

@@ -422,6 +430,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
 	return 0;
 
 err_out:
+	clk_disable_unprepare(icnclk);
 	clk_disable_unprepare(clk);
 err_of:
 	sdhci_pltfm_free(pdev);

@@ -442,6 +451,8 @@ static int sdhci_st_remove(struct platform_device *pdev)
 
 	ret = sdhci_pltfm_unregister(pdev);
 
+	clk_disable_unprepare(pdata->icnclk);
+
 	if (rstc)
 		reset_control_assert(rstc);
 

@@ -462,6 +473,7 @@ static int sdhci_st_suspend(struct device *dev)
 	if (pdata->rstc)
 		reset_control_assert(pdata->rstc);
 
+	clk_disable_unprepare(pdata->icnclk);
 	clk_disable_unprepare(pltfm_host->clk);
 out:
 	return ret;

@@ -475,6 +487,7 @@ static int sdhci_st_resume(struct device *dev)
 	struct device_node *np = dev->of_node;
 
 	clk_prepare_enable(pltfm_host->clk);
+	clk_prepare_enable(pdata->icnclk);
 
 	if (pdata->rstc)
 		reset_control_deassert(pdata->rstc);

-- 
2.9.3

The interconnect (ICN) clock is required for functional working of
MMC on some ST platforms.  When not supplied it can result in
broken MMC and the following output:

        [   13.916949] mmc0: Timeout waiting for hardware interrupt.
        [   13.922349] sdhci: =========== REGISTER DUMP (mmc0)===========
        [   13.928175] sdhci: Sys addr: 0x00000000 | Version:  0x00001002
        [   13.933999] sdhci: Blk size: 0x00007040 | Blk cnt:  0x00000001
        [   13.939825] sdhci: Argument: 0x00fffff0 | Trn mode: 0x00000013
        [   13.945650] sdhci: Present:  0x1fff0206 | Host ctl: 0x00000011
        [   13.951475] sdhci: Power:    0x0000000f | Blk gap:  0x00000080
        [   13.957300] sdhci: Wake-up:  0x00000000 | Clock:    0x00003f07
        [   13.963126] sdhci: Timeout:  0x00000004 | Int stat: 0x00000000
        [   13.968952] sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
        [   13.974777] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
        [   13.980602] sdhci: Caps:     0x21ed3281 | Caps_1:   0x00000000
        [   13.986428] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
        [   13.992252] sdhci: Host ctl2: 0x00000000
        [   13.996166] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x7c048200
        [   14.001990] sdhci: ===========================================
        [   14.009802] mmc0: Got data interrupt 0x02000000 even though no data operation was in progress.

Signed-off-by: Lee Jones <redacted>
---
 Documentation/devicetree/bindings/mmc/sdhci-st.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-st.txt b/Documentation/devicetree/bindings/mmc/sdhci-st.txt
index 88faa91..3cd4c43 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-st.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-st.txt

@@ -10,7 +10,7 @@ Required properties:
 			subsystem (mmcss) inside the FlashSS (available in STiH407 SoC
 			family).
 
-- clock-names:		Should be "mmc".
+- clock-names:		Should be "mmc" and "icn".  (NB: The latter is not compulsory)
 			See: Documentation/devicetree/bindings/resource-names.txt
 - clocks:		Phandle to the clock.
 			See: Documentation/devicetree/bindings/clock/clock-bindings.txt

-- 
2.9.3

The STiH4{07,10} platform contains some interconnect clocks which are used
by various IPs.  If this clock isn't handled correctly by ST's EHCI/OHCI
drivers, their hub won't be found, the following error be shown and the
result will be non-working USB:

  [   97.221963] hub 2-1:1.0: hub_ext_port_status failed (err = -110)

Cc: stable at vger.kernel.org
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <redacted>
---
 arch/arm/boot/dts/stih410.dtsi | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/stih410.dtsi b/arch/arm/boot/dts/stih410.dtsi
index 9ee5e20..f1aa34c 100644
--- a/arch/arm/boot/dts/stih410.dtsi
+++ b/arch/arm/boot/dts/stih410.dtsi

@@ -41,7 +41,8 @@
 			compatible = "st,st-ohci-300x";
 			reg = <0x9a03c00 0x100>;
 			interrupts = <GIC_SPI 180 IRQ_TYPE_NONE>;
-			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>;
+			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>,
+				 <&clk_s_c0_flexgen CLK_RX_ICN_DISP_0>;
 			resets = <&powerdown STIH407_USB2_PORT0_POWERDOWN>,
 				 <&softreset STIH407_USB2_PORT0_SOFTRESET>;
 			reset-names = "power", "softreset";

@@ -57,7 +58,8 @@
 			interrupts = <GIC_SPI 151 IRQ_TYPE_NONE>;
 			pinctrl-names = "default";
 			pinctrl-0 = <&pinctrl_usb0>;
-			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>;
+			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>,
+				 <&clk_s_c0_flexgen CLK_RX_ICN_DISP_0>;
 			resets = <&powerdown STIH407_USB2_PORT0_POWERDOWN>,
 				 <&softreset STIH407_USB2_PORT0_SOFTRESET>;
 			reset-names = "power", "softreset";

@@ -71,7 +73,8 @@
 			compatible = "st,st-ohci-300x";
 			reg = <0x9a83c00 0x100>;
 			interrupts = <GIC_SPI 181 IRQ_TYPE_NONE>;
-			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>;
+			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>,
+				 <&clk_s_c0_flexgen CLK_RX_ICN_DISP_0>;
 			resets = <&powerdown STIH407_USB2_PORT1_POWERDOWN>,
 				 <&softreset STIH407_USB2_PORT1_SOFTRESET>;
 			reset-names = "power", "softreset";

@@ -87,7 +90,8 @@
 			interrupts = <GIC_SPI 153 IRQ_TYPE_NONE>;
 			pinctrl-names = "default";
 			pinctrl-0 = <&pinctrl_usb1>;
-			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>;
+			clocks = <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>,
+				 <&clk_s_c0_flexgen CLK_RX_ICN_DISP_0>;
 			resets = <&powerdown STIH407_USB2_PORT1_POWERDOWN>,
 				 <&softreset STIH407_USB2_PORT1_SOFTRESET>;
 			reset-names = "power", "softreset";

-- 
2.9.3

Sorry Adrian, left you of the list.  Rectifying.

FYI, this patch is due for the v4.8 -rcs:

  http://www.spinics.net/lists/kernel/msg2338219.html

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Hi Lee


On 09/08/2016 11:11 AM, Lee Jones wrote:

Acked-by: Patrice Chotard <redacted>

Hi Lee


On 09/08/2016 11:11 AM, Lee Jones wrote:

Acked-by: Patrice Chotard <redacted>

Hi Lee

On 09/08/2016 11:11 AM, Lee Jones wrote:

Applied

thanks

Hi Lee


On 09/08/2016 11:11 AM, Lee Jones wrote:

Applied

Thanks

On 8 September 2016 at 11:11, Lee Jones [off-list ref] wrote:

This looks good to me!

I am guessing you want this to go through my mmc tree, as I think
patch 3 and patch 4 should go together. If not, tell me.

Kind regards
Uffe

On 9 September 2016 at 12:50, Ulf Hansson [off-list ref] wrote:

On 8 September 2016 at 11:11, Lee Jones [off-list ref] wrote:

quoted

The interconnect (ICN) clock is required for functional working of
MMC on some ST platforms.  When not supplied it can result in
broken MMC and the following output:

        [   13.916949] mmc0: Timeout waiting for hardware interrupt.
        [   13.922349] sdhci: =========== REGISTER DUMP (mmc0)===========
        [   13.928175] sdhci: Sys addr: 0x00000000 | Version:  0x00001002
        [   13.933999] sdhci: Blk size: 0x00007040 | Blk cnt:  0x00000001
        [   13.939825] sdhci: Argument: 0x00fffff0 | Trn mode: 0x00000013
        [   13.945650] sdhci: Present:  0x1fff0206 | Host ctl: 0x00000011
        [   13.951475] sdhci: Power:    0x0000000f | Blk gap:  0x00000080
        [   13.957300] sdhci: Wake-up:  0x00000000 | Clock:    0x00003f07
        [   13.963126] sdhci: Timeout:  0x00000004 | Int stat: 0x00000000
        [   13.968952] sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
        [   13.974777] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
        [   13.980602] sdhci: Caps:     0x21ed3281 | Caps_1:   0x00000000
        [   13.986428] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
        [   13.992252] sdhci: Host ctl2: 0x00000000
        [   13.996166] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x7c048200
        [   14.001990] sdhci: ===========================================
        [   14.009802] mmc0: Got data interrupt 0x02000000 even though no data operation was in progress.

Signed-off-by: Lee Jones <redacted>
---
 Documentation/devicetree/bindings/mmc/sdhci-st.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-st.txt b/Documentation/devicetree/bindings/mmc/sdhci-st.txt
index 88faa91..3cd4c43 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-st.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-st.txt

@@ -10,7 +10,7 @@ Required properties:
                        subsystem (mmcss) inside the FlashSS (available in STiH407 SoC
                        family).

-- clock-names:         Should be "mmc".
+- clock-names:         Should be "mmc" and "icn".  (NB: The latter is not compulsory)
                        See: Documentation/devicetree/bindings/resource-names.txt
 - clocks:              Phandle to the clock.
                        See: Documentation/devicetree/bindings/clock/clock-bindings.txt
--

2.9.3

This looks good to me!

I am guessing you want this to go through my mmc tree, as I think
patch 3 and patch 4 should go together. If not, tell me.

That's correct, thanks.

-- 
Lee Jones
Linaro ST Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

On 8 September 2016 at 11:11, Lee Jones [off-list ref] wrote:

The interconnect (ICN) clock is required for functional working of
MMC on some ST platforms.  When not supplied it can result in
broken MMC and the following output:

        [   13.916949] mmc0: Timeout waiting for hardware interrupt.
        [   13.922349] sdhci: =========== REGISTER DUMP (mmc0)===========
        [   13.928175] sdhci: Sys addr: 0x00000000 | Version:  0x00001002
        [   13.933999] sdhci: Blk size: 0x00007040 | Blk cnt:  0x00000001
        [   13.939825] sdhci: Argument: 0x00fffff0 | Trn mode: 0x00000013
        [   13.945650] sdhci: Present:  0x1fff0206 | Host ctl: 0x00000011
        [   13.951475] sdhci: Power:    0x0000000f | Blk gap:  0x00000080
        [   13.957300] sdhci: Wake-up:  0x00000000 | Clock:    0x00003f07
        [   13.963126] sdhci: Timeout:  0x00000004 | Int stat: 0x00000000
        [   13.968952] sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
        [   13.974777] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
        [   13.980602] sdhci: Caps:     0x21ed3281 | Caps_1:   0x00000000
        [   13.986428] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
        [   13.992252] sdhci: Host ctl2: 0x00000000
        [   13.996166] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x7c048200
        [   14.001990] sdhci: ===========================================
        [   14.009802] mmc0: Got data interrupt 0x02000000 even though no data operation was in progress.

Signed-off-by: Lee Jones <redacted>

Thanks, applied for fixes!

Kind regards
Uffe

On 8 September 2016 at 13:58, Lee Jones [off-list ref] wrote:

Sorry Adrian, left you of the list.  Rectifying.

FYI, this patch is due for the v4.8 -rcs:

  http://www.spinics.net/lists/kernel/msg2338219.html

quoted

Some ST platforms contain interconnect (ICN) clocks which must be handed
correctly in order to obtain full functionality of a given IP.  In this
case, if the ICN clocks are not handled properly by the ST SDHCI driver
MMC will break and the following output can be observed:

    [   13.916949] mmc0: Timeout waiting for hardware interrupt.
    [   13.922349] sdhci: =========== REGISTER DUMP (mmc0)===========
    [   13.928175] sdhci: Sys addr: 0x00000000 | Version:  0x00001002
    [   13.933999] sdhci: Blk size: 0x00007040 | Blk cnt:  0x00000001
    [   13.939825] sdhci: Argument: 0x00fffff0 | Trn mode: 0x00000013
    [   13.945650] sdhci: Present:  0x1fff0206 | Host ctl: 0x00000011
    [   13.951475] sdhci: Power:    0x0000000f | Blk gap:  0x00000080
    [   13.957300] sdhci: Wake-up:  0x00000000 | Clock:    0x00003f07
    [   13.963126] sdhci: Timeout:  0x00000004 | Int stat: 0x00000000
    [   13.968952] sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
    [   13.974777] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
    [   13.980602] sdhci: Caps:     0x21ed3281 | Caps_1:   0x00000000
    [   13.986428] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
    [   13.992252] sdhci: Host ctl2: 0x00000000
    [   13.996166] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x7c048200
    [   14.001990] sdhci: ===========================================
    [   14.009802] mmc0: Got data interrupt 0x02000000 even though no data operation was in progress.

A decent point was raised about minimising the use of a local variable that
we 'could' do without.  I've chosen consistency over the possibility of
reducing the local variable count by 1.  Thinking that it's more important
for the code to be grouped and authoured in a similar manner/style for
greater maintainability/readability.

Cc: stable at vger.kernel.org
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <redacted>

Thanks, applied for fixes!

Adrian, please tell if you have any objections else I intend to send
this for the rcs later this week.

Kind regards
Uffe

quoted

---
 drivers/mmc/host/sdhci-st.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-st.c b/drivers/mmc/host/sdhci-st.c
index c95ba83..ed92ce7 100644
--- a/drivers/mmc/host/sdhci-st.c
+++ b/drivers/mmc/host/sdhci-st.c

@@ -28,6 +28,7 @@

 struct st_mmc_platform_data {
      struct  reset_control *rstc;
+     struct  clk *icnclk;
      void __iomem *top_ioaddr;
 };

@@ -353,7 +354,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
      struct sdhci_host *host;
      struct st_mmc_platform_data *pdata;
      struct sdhci_pltfm_host *pltfm_host;
-     struct clk *clk;
+     struct clk *clk, *icnclk;
      int ret = 0;
      u16 host_version;
      struct resource *res;

@@ -365,6 +366,11 @@ static int sdhci_st_probe(struct platform_device *pdev)
              return PTR_ERR(clk);
      }

+     /* ICN clock isn't compulsory, but use it if it's provided. */
+     icnclk = devm_clk_get(&pdev->dev, "icn");
+     if (IS_ERR(icnclk))
+             icnclk = NULL;
+
      rstc = devm_reset_control_get(&pdev->dev, NULL);
      if (IS_ERR(rstc))
              rstc = NULL;

@@ -389,6 +395,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
      }

      clk_prepare_enable(clk);
+     clk_prepare_enable(icnclk);

      /* Configure the FlashSS Top registers for setting eMMC TX/RX delay */
      res = platform_get_resource_byname(pdev, IORESOURCE_MEM,

@@ -400,6 +407,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
      }

      pltfm_host->clk = clk;
+     pdata->icnclk = icnclk;

      /* Configure the Arasan HC inside the flashSS */
      st_mmcss_cconfig(np, host);

@@ -422,6 +430,7 @@ static int sdhci_st_probe(struct platform_device *pdev)
      return 0;

 err_out:
+     clk_disable_unprepare(icnclk);
      clk_disable_unprepare(clk);
 err_of:
      sdhci_pltfm_free(pdev);

@@ -442,6 +451,8 @@ static int sdhci_st_remove(struct platform_device *pdev)

      ret = sdhci_pltfm_unregister(pdev);

+     clk_disable_unprepare(pdata->icnclk);
+
      if (rstc)
              reset_control_assert(rstc);

@@ -462,6 +473,7 @@ static int sdhci_st_suspend(struct device *dev)
      if (pdata->rstc)
              reset_control_assert(pdata->rstc);

+     clk_disable_unprepare(pdata->icnclk);
      clk_disable_unprepare(pltfm_host->clk);
 out:
      return ret;

@@ -475,6 +487,7 @@ static int sdhci_st_resume(struct device *dev)
      struct device_node *np = dev->of_node;

      clk_prepare_enable(pltfm_host->clk);
+     clk_prepare_enable(pdata->icnclk);

      if (pdata->rstc)
              reset_control_deassert(pdata->rstc);

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog