[PATCH 0/2] can: flexcan: fix regression from v4.16-rc1

[PATCH 0/2] can: flexcan: fix regression from v4.16-rc1

[Uwe Kleine-König]

Hello,

when porting the kernel from a i.MX25 based machine to 4.17-rc1 (but
still using the old dtb) can failed to probe. After some research we
noticed that a commit that was merged in the v4.16 merge window
introduced a change that broke using an older device tree.

This series first commit fixes the issue.
The second patch introduces a fallback compatible which matches the
usual dt-style on i.MX. (Before v4.16-rc1 there was a wrong fallback
compatible that was removed.)

Best regards
Uwe

Uwe Kleine-König (2):
  can: flexcan: fix endianess detection
  arm: dts: imx[35]*: declare flexcan devices to be compatible to
    imx25's flexcan

 arch/arm/boot/dts/imx35.dtsi |  4 ++--
 arch/arm/boot/dts/imx53.dtsi |  4 ++--
 drivers/net/can/flexcan.c    | 26 ++++++++++++++------------
 3 files changed, 18 insertions(+), 16 deletions(-)

-- 
2.17.0


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[PATCH 1/2] can: flexcan: fix endianess detection

[Uwe Kleine-König]

In commit 88462d2a7830 ("can: flexcan: Remodel FlexCAN register r/w APIs
for big endian FlexCAN controllers.") the following logic was
implemented:

	if the dt property "big-endian" is given or
	   the device is compatible to "fsl,p1010-flexcan":
		use big-endian mode;
	else
		use little-endian mode;

This relies on commit d50f4630c2e1 ("arm: dts: Remove p1010-flexcan
compatible from imx series dts") which was applied a few commits later.
Without this commit (or an old device tree used for booting a new
kernel) the flexcan devices on i.MX25, i.MX28, i.MX35 and i.MX53 match
the 'the device is compatible to "fsl,p1010-flexcan"' test and so are
switched erroneously to big endian mode.

Instead of the check above put a flag into devtype data and rely on
of_match_device yielding the most compatible match

Fixes: 88462d2a7830 ("can: flexcan: Remodel FlexCAN register r/w APIs for big endian FlexCAN controllers.")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/net/can/flexcan.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 634c51e6b8ae..a6cbbe689eab 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -262,6 +262,7 @@ struct flexcan_regs {
 
 struct flexcan_devtype_data {
 	u32 quirks;		/* quirks needed for different IP cores */
+	bool default_be;
 };
 
 struct flexcan_priv {
@@ -289,6 +290,12 @@ struct flexcan_priv {
 static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
 		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+	.default_be = true,
+};
+
+static const struct flexcan_devtype_data fsl_imx25_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
 };
 
 static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
@@ -1251,9 +1258,9 @@ static void unregister_flexcandev(struct net_device *dev)
 static const struct of_device_id flexcan_of_match[] = {
 	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
 	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
-	{ .compatible = "fsl,imx53-flexcan", .data = &fsl_p1010_devtype_data, },
-	{ .compatible = "fsl,imx35-flexcan", .data = &fsl_p1010_devtype_data, },
-	{ .compatible = "fsl,imx25-flexcan", .data = &fsl_p1010_devtype_data, },
+	{ .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
+	{ .compatible = "fsl,imx35-flexcan", .data = &fsl_imx25_devtype_data, },
+	{ .compatible = "fsl,imx25-flexcan", .data = &fsl_imx25_devtype_data, },
 	{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
 	{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
 	{ .compatible = "fsl,ls1021ar2-flexcan", .data = &fsl_ls1021a_r2_devtype_data, },
@@ -1337,18 +1344,13 @@ static int flexcan_probe(struct platform_device *pdev)
 
 	priv = netdev_priv(dev);
 
-	if (of_property_read_bool(pdev->dev.of_node, "big-endian")) {
+	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
+	    devtype_data->default_be) {
 		priv->read = flexcan_read_be;
 		priv->write = flexcan_write_be;
 	} else {
-		if (of_device_is_compatible(pdev->dev.of_node,
-					    "fsl,p1010-flexcan")) {
-			priv->read = flexcan_read_be;
-			priv->write = flexcan_write_be;
-		} else {
-			priv->read = flexcan_read_le;
-			priv->write = flexcan_write_le;
-		}
+		priv->read = flexcan_read_le;
+		priv->write = flexcan_write_le;
 	}
 
 	priv->can.clock.freq = clock_freq;
-- 
2.17.0


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[PATCH 2/2] arm: dts: imx[35]*: declare flexcan devices to be compatible to imx25's flexcan

[Uwe Kleine-König]

Commit d50f4630c2e1 ("arm: dts: Remove p1010-flexcan compatible from imx
series dts") removed the fallback compatible "fsl,p1010-flexcan" from
the imx device trees. As the flexcan cores on i.MX25, i.MX35 and i.MX53
are identical, introduce the first as fallback for the two latter ones.

Fixes: d50f4630c2e1 ("arm: dts: Remove p1010-flexcan compatible from imx series dts")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 arch/arm/boot/dts/imx35.dtsi | 4 ++--
 arch/arm/boot/dts/imx53.dtsi | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/imx35.dtsi b/arch/arm/boot/dts/imx35.dtsi
index bf343195697e..54111ed218b1 100644
--- a/arch/arm/boot/dts/imx35.dtsi
+++ b/arch/arm/boot/dts/imx35.dtsi
@@ -303,7 +303,7 @@
 			};
 
 			can1: can@53fe4000 {
-				compatible = "fsl,imx35-flexcan";
+				compatible = "fsl,imx35-flexcan", "fsl,imx25-flexcan";
 				reg = <0x53fe4000 0x1000>;
 				clocks = <&clks 33>, <&clks 33>;
 				clock-names = "ipg", "per";
@@ -312,7 +312,7 @@
 			};
 
 			can2: can@53fe8000 {
-				compatible = "fsl,imx35-flexcan";
+				compatible = "fsl,imx35-flexcan", "fsl,imx25-flexcan";
 				reg = <0x53fe8000 0x1000>;
 				clocks = <&clks 34>, <&clks 34>;
 				clock-names = "ipg", "per";
diff --git a/arch/arm/boot/dts/imx53.dtsi b/arch/arm/boot/dts/imx53.dtsi
index 7d647d043f52..3d65c0192f69 100644
--- a/arch/arm/boot/dts/imx53.dtsi
+++ b/arch/arm/boot/dts/imx53.dtsi
@@ -551,7 +551,7 @@
 			};
 
 			can1: can@53fc8000 {
-				compatible = "fsl,imx53-flexcan";
+				compatible = "fsl,imx53-flexcan", "fsl,imx25-flexcan";
 				reg = <0x53fc8000 0x4000>;
 				interrupts = <82>;
 				clocks = <&clks IMX5_CLK_CAN1_IPG_GATE>,
@@ -561,7 +561,7 @@
 			};
 
 			can2: can@53fcc000 {
-				compatible = "fsl,imx53-flexcan";
+				compatible = "fsl,imx53-flexcan", "fsl,imx25-flexcan";
 				reg = <0x53fcc000 0x4000>;
 				interrupts = <83>;
 				clocks = <&clks IMX5_CLK_CAN2_IPG_GATE>,
-- 
2.17.0


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Re: [PATCH 0/2] can: flexcan: fix regression from v4.16-rc1

[Marc Kleine-Budde]

[-- Attachment #1.1.1: Type: text/plain, Size: 898 bytes --]

On 04/25/2018 04:50 PM, Uwe Kleine-König wrote:
> Hello,
> 
> when porting the kernel from a i.MX25 based machine to 4.17-rc1 (but
> still using the old dtb) can failed to probe. After some research we
> noticed that a commit that was merged in the v4.16 merge window
> introduced a change that broke using an older device tree.
> 
> This series first commit fixes the issue.
> The second patch introduces a fallback compatible which matches the
> usual dt-style on i.MX. (Before v4.16-rc1 there was a wrong fallback
> compatible that was removed.)

Applied both to linux-can + added stable on Cc.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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Re: [PATCH 1/2] can: flexcan: fix endianess detection

[Schenk, Gavin]

Hi,

> In commit 88462d2a7830 ("can: flexcan: Remodel FlexCAN register r/w APIs
> for big endian FlexCAN controllers.") the following logic was
> implemented:
> 
> 	if the dt property "big-endian" is given or
> 	   the device is compatible to "fsl,p1010-flexcan":
> 		use big-endian mode;
> 	else
> 		use little-endian mode;
> 
> This relies on commit d50f4630c2e1 ("arm: dts: Remove p1010-flexcan
> compatible from imx series dts") which was applied a few commits later.
> Without this commit (or an old device tree used for booting a new
> kernel) the flexcan devices on i.MX25, i.MX28, i.MX35 and i.MX53 match
> the 'the device is compatible to "fsl,p1010-flexcan"' test and so are
> switched erroneously to big endian mode.
> 
> Instead of the check above put a flag into devtype data and rely on
> of_match_device yielding the most compatible match
> 
> Fixes: 88462d2a7830 ("can: flexcan: Remodel FlexCAN register r/w APIs for big
> endian FlexCAN controllers.")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Gavin Schenk <g.schenk@eckelmann.de>

Regards
Gavin Schenk
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Re: [PATCH 1/2] can: flexcan: fix endianess detection

[Marc Kleine-Budde]

[-- Attachment #1.1.1: Type: text/plain, Size: 1908 bytes --]

On 04/25/2018 04:50 PM, Uwe Kleine-König wrote:
> In commit 88462d2a7830 ("can: flexcan: Remodel FlexCAN register r/w APIs
> for big endian FlexCAN controllers.") the following logic was
> implemented:
> 
> 	if the dt property "big-endian" is given or
> 	   the device is compatible to "fsl,p1010-flexcan":
> 		use big-endian mode;
> 	else
> 		use little-endian mode;
> 
> This relies on commit d50f4630c2e1 ("arm: dts: Remove p1010-flexcan
> compatible from imx series dts") which was applied a few commits later.
> Without this commit (or an old device tree used for booting a new
> kernel) the flexcan devices on i.MX25, i.MX28, i.MX35 and i.MX53 match
> the 'the device is compatible to "fsl,p1010-flexcan"' test and so are
> switched erroneously to big endian mode.
> 
> Instead of the check above put a flag into devtype data and rely on
> of_match_device yielding the most compatible match
> 
> Fixes: 88462d2a7830 ("can: flexcan: Remodel FlexCAN register r/w APIs for big endian FlexCAN controllers.")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/net/can/flexcan.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index 634c51e6b8ae..a6cbbe689eab 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -262,6 +262,7 @@ struct flexcan_regs {
>  
>  struct flexcan_devtype_data {
>  	u32 quirks;		/* quirks needed for different IP cores */
> +	bool default_be;
>  };

What about adding this to quirks?

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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