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* [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
@ 2020-03-25 11:34 Ulf Hansson
  2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
                   ` (2 more replies)
  0 siblings, 3 replies; 13+ messages in thread
From: Ulf Hansson @ 2020-03-25 11:34 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Haibo Chen, Ludovic Barre, linux-arm-kernel,
	dmaengine, Ulf Hansson

It's currently the amba/platform driver's responsibility to initialize the
pointer, dma_parms, for its corresponding struct device. The benefit with this
approach allows us to avoid the initialization and to not waste memory for the
struct device_dma_parameters, as this can be decided on a case by case basis.
    
However, it has turned out that this approach is not very practical. Not only
does it lead to open coding, but also to real errors. In principle callers of
dma_set_max_seg_size() doesn't check the error code, but just assumes it
succeeds.
    
For these reasons, this series initializes the dma_parms from the amba/platform
bus at the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().

If it turns out that this is an acceptable solution, we probably also want the
changes for stable, but I am not sure if it applies without conflicts.

The series is based on v5.6-rc7.

Kind regards
Ulf Hansson

Ulf Hansson (2):
  driver core: platform: Initialize dma_parms for platform devices
  amba: Initialize dma_parms for amba devices

 drivers/amba/bus.c              | 2 ++
 drivers/base/platform.c         | 1 +
 include/linux/amba/bus.h        | 1 +
 include/linux/platform_device.h | 1 +
 4 files changed, 5 insertions(+)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices
  2020-03-25 11:34 [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level Ulf Hansson
@ 2020-03-25 11:34 ` Ulf Hansson
  2020-03-25 15:23   ` Ludovic BARRE
                     ` (2 more replies)
  2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson
  2020-03-26  4:41 ` [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level BOUGH CHEN
  2 siblings, 3 replies; 13+ messages in thread
From: Ulf Hansson @ 2020-03-25 11:34 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Haibo Chen, Ludovic Barre, linux-arm-kernel,
	dmaengine, Ulf Hansson, stable

It's currently the platform driver's responsibility to initialize the
pointer, dma_parms, for its corresponding struct device. The benefit with
this approach allows us to avoid the initialization and to not waste memory
for the struct device_dma_parameters, as this can be decided on a case by
case basis.

However, it has turned out that this approach is not very practical.  Not
only does it lead to open coding, but also to real errors. In principle
callers of dma_set_max_seg_size() doesn't check the error code, but just
assumes it succeeds.

For these reasons, let's do the initialization from the common platform bus
at the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().

Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/platform.c         | 1 +
 include/linux/platform_device.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b5ce7b085795..46abbfb52655 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -512,6 +512,7 @@ int platform_device_add(struct platform_device *pdev)
 		pdev->dev.parent = &platform_bus;
 
 	pdev->dev.bus = &platform_bus_type;
+	pdev->dev.dma_parms = &pdev->dma_parms;
 
 	switch (pdev->id) {
 	default:
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 041bfa412aa0..81900b3cbe37 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -25,6 +25,7 @@ struct platform_device {
 	bool		id_auto;
 	struct device	dev;
 	u64		platform_dma_mask;
+	struct device_dma_parameters dma_parms;
 	u32		num_resources;
 	struct resource	*resource;
 
-- 
2.20.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH 2/2] amba: Initialize dma_parms for amba devices
  2020-03-25 11:34 [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level Ulf Hansson
  2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
@ 2020-03-25 11:34 ` Ulf Hansson
  2020-03-25 15:24   ` Ludovic BARRE
                     ` (2 more replies)
  2020-03-26  4:41 ` [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level BOUGH CHEN
  2 siblings, 3 replies; 13+ messages in thread
From: Ulf Hansson @ 2020-03-25 11:34 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Haibo Chen, Ludovic Barre, linux-arm-kernel,
	dmaengine, Ulf Hansson, stable

It's currently the amba driver's responsibility to initialize the pointer,
dma_parms, for its corresponding struct device. The benefit with this
approach allows us to avoid the initialization and to not waste memory for
the struct device_dma_parameters, as this can be decided on a case by case
basis.

However, it has turned out that this approach is not very practical. Not
only does it lead to open coding, but also to real errors. In principle
callers of dma_set_max_seg_size() doesn't check the error code, but just
assumes it succeeds.

For these reasons, let's do the initialization from the common amba bus at
the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().

Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/amba/bus.c       | 2 ++
 include/linux/amba/bus.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index fe1523664816..5e61783ce92d 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -374,6 +374,8 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
 	WARN_ON(dev->irq[0] == (unsigned int)-1);
 	WARN_ON(dev->irq[1] == (unsigned int)-1);
 
+	dev->dev.dma_parms = &dev->dma_parms;
+
 	ret = request_resource(parent, &dev->res);
 	if (ret)
 		goto err_out;
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index 26f0ecf401ea..0bbfd647f5c6 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -65,6 +65,7 @@ struct amba_device {
 	struct device		dev;
 	struct resource		res;
 	struct clk		*pclk;
+	struct device_dma_parameters dma_parms;
 	unsigned int		periphid;
 	unsigned int		cid;
 	struct amba_cs_uci_id	uci;
-- 
2.20.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices
  2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
@ 2020-03-25 15:23   ` Ludovic BARRE
  2020-03-26 11:01   ` Linus Walleij
  2020-03-26 11:06   ` Arnd Bergmann
  2 siblings, 0 replies; 13+ messages in thread
From: Ludovic BARRE @ 2020-03-25 15:23 UTC (permalink / raw)
  To: Ulf Hansson, Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Haibo Chen, linux-arm-kernel, dmaengine, stable



Le 3/25/20 à 12:34 PM, Ulf Hansson a écrit :
> It's currently the platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with
> this approach allows us to avoid the initialization and to not waste memory
> for the struct device_dma_parameters, as this can be decided on a case by
> case basis.
> 
> However, it has turned out that this approach is not very practical.  Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
> 
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().

tested with mmc: mmci_sdmmc fix
Tested-by: Ludovic Barre <ludovic.barre@st.com>

> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>   drivers/base/platform.c         | 1 +
>   include/linux/platform_device.h | 1 +
>   2 files changed, 2 insertions(+)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index b5ce7b085795..46abbfb52655 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -512,6 +512,7 @@ int platform_device_add(struct platform_device *pdev)
>   		pdev->dev.parent = &platform_bus;
>   
>   	pdev->dev.bus = &platform_bus_type;
> +	pdev->dev.dma_parms = &pdev->dma_parms;
>   
>   	switch (pdev->id) {
>   	default:
> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 041bfa412aa0..81900b3cbe37 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -25,6 +25,7 @@ struct platform_device {
>   	bool		id_auto;
>   	struct device	dev;
>   	u64		platform_dma_mask;
> +	struct device_dma_parameters dma_parms;
>   	u32		num_resources;
>   	struct resource	*resource;
>   
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/2] amba: Initialize dma_parms for amba devices
  2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson
@ 2020-03-25 15:24   ` Ludovic BARRE
  2020-03-26 11:02   ` Linus Walleij
  2020-03-26 11:07   ` Arnd Bergmann
  2 siblings, 0 replies; 13+ messages in thread
From: Ludovic BARRE @ 2020-03-25 15:24 UTC (permalink / raw)
  To: Ulf Hansson, Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Haibo Chen, linux-arm-kernel, dmaengine, stable



Le 3/25/20 à 12:34 PM, Ulf Hansson a écrit :
> It's currently the amba driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
> 
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
> 
> For these reasons, let's do the initialization from the common amba bus at
> the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
> 

tested with mmc: mmci_sdmmc fix
Tested-by: Ludovic Barre <ludovic.barre@st.com>

> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>   drivers/amba/bus.c       | 2 ++
>   include/linux/amba/bus.h | 1 +
>   2 files changed, 3 insertions(+)
> 
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index fe1523664816..5e61783ce92d 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -374,6 +374,8 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
>   	WARN_ON(dev->irq[0] == (unsigned int)-1);
>   	WARN_ON(dev->irq[1] == (unsigned int)-1);
>   
> +	dev->dev.dma_parms = &dev->dma_parms;
> +
>   	ret = request_resource(parent, &dev->res);
>   	if (ret)
>   		goto err_out;
> diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
> index 26f0ecf401ea..0bbfd647f5c6 100644
> --- a/include/linux/amba/bus.h
> +++ b/include/linux/amba/bus.h
> @@ -65,6 +65,7 @@ struct amba_device {
>   	struct device		dev;
>   	struct resource		res;
>   	struct clk		*pclk;
> +	struct device_dma_parameters dma_parms;
>   	unsigned int		periphid;
>   	unsigned int		cid;
>   	struct amba_cs_uci_id	uci;
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
  2020-03-25 11:34 [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level Ulf Hansson
  2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
  2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson
@ 2020-03-26  4:41 ` BOUGH CHEN
  2020-03-27  3:02   ` BOUGH CHEN
  2 siblings, 1 reply; 13+ messages in thread
From: BOUGH CHEN @ 2020-03-26  4:41 UTC (permalink / raw)
  To: Ulf Hansson, Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Ludovic Barre, linux-arm-kernel, dmaengine

> -----Original Message-----
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Sent: 2020年3月25日 19:34
> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rafael J . Wysocki
> <rafael@kernel.org>; linux-kernel@vger.kernel.org
> Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> Russell King <linux@armlinux.org.uk>; Linus Walleij
> <linus.walleij@linaro.org>; Vinod Koul <vkoul@kernel.org>; BOUGH CHEN
> <haibo.chen@nxp.com>; Ludovic Barre <ludovic.barre@st.com>;
> linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org; Ulf
> Hansson <ulf.hansson@linaro.org>
> Subject: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
> 
> It's currently the amba/platform driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
> 
> However, it has turned out that this approach is not very practical. Not only
> does it lead to open coding, but also to real errors. In principle callers of
> dma_set_max_seg_size() doesn't check the error code, but just assumes it
> succeeds.
> 
> For these reasons, this series initializes the dma_parms from the
> amba/platform bus at the device registration point. This also follows the
> way the PCI devices are being managed, see pci_device_add().
> 
> If it turns out that this is an acceptable solution, we probably also want the
> changes for stable, but I am not sure if it applies without conflicts.
> 
> The series is based on v5.6-rc7.
> 

Hi Ulf,

Since i.MXQM SMMU related code still not upstream yet, so I apply your patches on our internal Linux branch based on v5.4.24, and find it do not work on my side. Maybe for platform core drivers, there is a gap between v5.4.24 and v5.6-rc7 which has the impact.
I will try to put our SMMU related code into v5.6-rc7, then do the test again.


Best Regards
Haibo Chen

> Kind regards
> Ulf Hansson
> 
> Ulf Hansson (2):
>   driver core: platform: Initialize dma_parms for platform devices
>   amba: Initialize dma_parms for amba devices
> 
>  drivers/amba/bus.c              | 2 ++
>  drivers/base/platform.c         | 1 +
>  include/linux/amba/bus.h        | 1 +
>  include/linux/platform_device.h | 1 +
>  4 files changed, 5 insertions(+)
> 
> --
> 2.20.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices
  2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
  2020-03-25 15:23   ` Ludovic BARRE
@ 2020-03-26 11:01   ` Linus Walleij
  2020-03-26 11:06   ` Arnd Bergmann
  2 siblings, 0 replies; 13+ messages in thread
From: Linus Walleij @ 2020-03-26 11:01 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel,
	Arnd Bergmann, Christoph Hellwig, Russell King, Vinod Koul,
	Haibo Chen, Ludovic Barre, Linux ARM, dmaengine, stable

On Wed, Mar 25, 2020 at 12:34 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:

> It's currently the platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with
> this approach allows us to avoid the initialization and to not waste memory
> for the struct device_dma_parameters, as this can be decided on a case by
> case basis.
>
> However, it has turned out that this approach is not very practical.  Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

This seems in line with what Christoph said.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

I imagine we can eventually set up more of the DMA config such
as segment size based on config from the device tree, but I'm not
sure about that yet.

Yours,
Linus Walleij

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/2] amba: Initialize dma_parms for amba devices
  2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson
  2020-03-25 15:24   ` Ludovic BARRE
@ 2020-03-26 11:02   ` Linus Walleij
  2020-03-26 11:07   ` Arnd Bergmann
  2 siblings, 0 replies; 13+ messages in thread
From: Linus Walleij @ 2020-03-26 11:02 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel,
	Arnd Bergmann, Christoph Hellwig, Russell King, Vinod Koul,
	Haibo Chen, Ludovic Barre, Linux ARM, dmaengine, stable

On Wed, Mar 25, 2020 at 12:34 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:

> It's currently the amba driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common amba bus at
> the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices
  2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
  2020-03-25 15:23   ` Ludovic BARRE
  2020-03-26 11:01   ` Linus Walleij
@ 2020-03-26 11:06   ` Arnd Bergmann
  2 siblings, 0 replies; 13+ messages in thread
From: Arnd Bergmann @ 2020-03-26 11:06 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel,
	Christoph Hellwig, Russell King, Linus Walleij, Vinod Koul,
	Haibo Chen, Ludovic Barre, Linux ARM, dmaengine, # 3.4.x

On Wed, Mar 25, 2020 at 12:34 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with
> this approach allows us to avoid the initialization and to not waste memory
> for the struct device_dma_parameters, as this can be decided on a case by
> case basis.
>
> However, it has turned out that this approach is not very practical.  Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Acked-by: Arnd Bergmann <arnd@arndb.de>

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/2] amba: Initialize dma_parms for amba devices
  2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson
  2020-03-25 15:24   ` Ludovic BARRE
  2020-03-26 11:02   ` Linus Walleij
@ 2020-03-26 11:07   ` Arnd Bergmann
  2 siblings, 0 replies; 13+ messages in thread
From: Arnd Bergmann @ 2020-03-26 11:07 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel,
	Christoph Hellwig, Russell King, Linus Walleij, Vinod Koul,
	Haibo Chen, Ludovic Barre, Linux ARM, dmaengine, # 3.4.x

On Wed, Mar 25, 2020 at 12:34 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the amba driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common amba bus at
> the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Acked-by: Arnd Bergmann <arnd@arndb.de>

^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
  2020-03-26  4:41 ` [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level BOUGH CHEN
@ 2020-03-27  3:02   ` BOUGH CHEN
  2020-03-27 15:34     ` Ulf Hansson
  0 siblings, 1 reply; 13+ messages in thread
From: BOUGH CHEN @ 2020-03-27  3:02 UTC (permalink / raw)
  To: Ulf Hansson, Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
  Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Ludovic Barre, linux-arm-kernel, dmaengine


> -----Original Message-----
> From: BOUGH CHEN
> Sent: 2020年3月26日 12:41
> To: Ulf Hansson <ulf.hansson@linaro.org>; Greg Kroah-Hartman
> <gregkh@linuxfoundation.org>; Rafael J . Wysocki <rafael@kernel.org>;
> linux-kernel@vger.kernel.org
> Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> Russell King <linux@armlinux.org.uk>; Linus Walleij <linus.walleij@linaro.org>;
> Vinod Koul <vkoul@kernel.org>; Ludovic Barre <ludovic.barre@st.com>;
> linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org
> Subject: RE: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
> 
> > -----Original Message-----
> > From: Ulf Hansson <ulf.hansson@linaro.org>
> > Sent: 2020年3月25日 19:34
> > To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rafael J .
> > Wysocki <rafael@kernel.org>; linux-kernel@vger.kernel.org
> > Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> > Russell King <linux@armlinux.org.uk>; Linus Walleij
> > <linus.walleij@linaro.org>; Vinod Koul <vkoul@kernel.org>; BOUGH CHEN
> > <haibo.chen@nxp.com>; Ludovic Barre <ludovic.barre@st.com>;
> > linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org; Ulf
> > Hansson <ulf.hansson@linaro.org>
> > Subject: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus
> > level
> >
> > It's currently the amba/platform driver's responsibility to initialize
> > the pointer, dma_parms, for its corresponding struct device. The
> > benefit with this approach allows us to avoid the initialization and
> > to not waste memory for the struct device_dma_parameters, as this can
> > be decided on a case by case basis.
> >
> > However, it has turned out that this approach is not very practical.
> > Not only does it lead to open coding, but also to real errors. In
> > principle callers of
> > dma_set_max_seg_size() doesn't check the error code, but just assumes
> > it succeeds.
> >
> > For these reasons, this series initializes the dma_parms from the
> > amba/platform bus at the device registration point. This also follows
> > the way the PCI devices are being managed, see pci_device_add().
> >
> > If it turns out that this is an acceptable solution, we probably also
> > want the changes for stable, but I am not sure if it applies without conflicts.
> >
> > The series is based on v5.6-rc7.
> >
> 
> Hi Ulf,
> 
> Since i.MXQM SMMU related code still not upstream yet, so I apply your
> patches on our internal Linux branch based on v5.4.24, and find it do not work
> on my side. Maybe for platform core drivers, there is a gap between v5.4.24
> and v5.6-rc7 which has the impact.
> I will try to put our SMMU related code into v5.6-rc7, then do the test again.
> 
> 

Hi Ulf,

On the latest Linux-next branch, the top commit 89295c59c1f063b533d071ca49d0fa0c0783ca6f (tag: next-20200326), after add your two patches, I just add the simple debug code as following in the /driver/mmc/core/queue.c, but seems still not work as our expect, logically, it should work, so can you or anyone test on other platform? This seems weird.

diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 25bee3daf9e2..f091280f7ffb 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -403,6 +403,13 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
                blk_queue_max_segment_size(mq->queue,
                        round_down(host->max_seg_size, block_size));

+       pr_err("###### the max segment size is %d\n", queue_max_segment_size(mq->queue));
+       if (host->parent->dma_parms) {
+                      pr_err("######### the dma parms has value\n");
+       } else if (!(host->parent->dma_parms)) {
+                      pr_err("######## the dma parms is zero!!\n");
+       }
+
        dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));

        INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);

Here is the log I got when system run, even after your patch, the dev->dma_parms is still NULL. 
[    0.989853] mmc0: new HS400 MMC card at address 0001
[    0.995708] sdhci-esdhc-imx 30b50000.mmc: Got CD GPIO
[    0.999374] ###### the max segment size is 65024
[    1.008594] ######## the dma parms is zero!!
[    1.012875] mmcblk0: mmc0:0001 IB2932 29.2 GiB
[    1.017569] ###### the max segment size is 65024
[    1.022195] ######## the dma parms is zero!!
[    1.026479] mmcblk0boot0: mmc0:0001 IB2932 partition 1 4.00 MiB
[    1.032541] ###### the max segment size is 65024
[    1.035198] mmc1: SDHCI controller on 30b50000.mmc [30b50000.mmc] using ADMA
[    1.037169] ######## the dma parms is zero!!
[    1.048493] mmcblk0boot1: mmc0:0001 IB2932 partition 2 4.00 MiB
[    1.054531] mmcblk0rpmb: mmc0:0001 IB2932 partition 3 4.00 MiB, chardev (234:0)


Regards
Haibo Chen
> Best Regards
> Haibo Chen
> 
> > Kind regards
> > Ulf Hansson
> >
> > Ulf Hansson (2):
> >   driver core: platform: Initialize dma_parms for platform devices
> >   amba: Initialize dma_parms for amba devices
> >
> >  drivers/amba/bus.c              | 2 ++
> >  drivers/base/platform.c         | 1 +
> >  include/linux/amba/bus.h        | 1 +
> >  include/linux/platform_device.h | 1 +
> >  4 files changed, 5 insertions(+)
> >
> > --
> > 2.20.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
  2020-03-27  3:02   ` BOUGH CHEN
@ 2020-03-27 15:34     ` Ulf Hansson
  2020-03-27 19:15       ` Robin Murphy
  0 siblings, 1 reply; 13+ messages in thread
From: Ulf Hansson @ 2020-03-27 15:34 UTC (permalink / raw)
  To: BOUGH CHEN
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel,
	Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
	Vinod Koul, Ludovic Barre, linux-arm-kernel, dmaengine

On Fri, 27 Mar 2020 at 04:02, BOUGH CHEN <haibo.chen@nxp.com> wrote:
>
>
> > -----Original Message-----
> > From: BOUGH CHEN
> > Sent: 2020年3月26日 12:41
> > To: Ulf Hansson <ulf.hansson@linaro.org>; Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org>; Rafael J . Wysocki <rafael@kernel.org>;
> > linux-kernel@vger.kernel.org
> > Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> > Russell King <linux@armlinux.org.uk>; Linus Walleij <linus.walleij@linaro.org>;
> > Vinod Koul <vkoul@kernel.org>; Ludovic Barre <ludovic.barre@st.com>;
> > linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org
> > Subject: RE: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
> >
> > > -----Original Message-----
> > > From: Ulf Hansson <ulf.hansson@linaro.org>
> > > Sent: 2020年3月25日 19:34
> > > To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rafael J .
> > > Wysocki <rafael@kernel.org>; linux-kernel@vger.kernel.org
> > > Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> > > Russell King <linux@armlinux.org.uk>; Linus Walleij
> > > <linus.walleij@linaro.org>; Vinod Koul <vkoul@kernel.org>; BOUGH CHEN
> > > <haibo.chen@nxp.com>; Ludovic Barre <ludovic.barre@st.com>;
> > > linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org; Ulf
> > > Hansson <ulf.hansson@linaro.org>
> > > Subject: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus
> > > level
> > >
> > > It's currently the amba/platform driver's responsibility to initialize
> > > the pointer, dma_parms, for its corresponding struct device. The
> > > benefit with this approach allows us to avoid the initialization and
> > > to not waste memory for the struct device_dma_parameters, as this can
> > > be decided on a case by case basis.
> > >
> > > However, it has turned out that this approach is not very practical.
> > > Not only does it lead to open coding, but also to real errors. In
> > > principle callers of
> > > dma_set_max_seg_size() doesn't check the error code, but just assumes
> > > it succeeds.
> > >
> > > For these reasons, this series initializes the dma_parms from the
> > > amba/platform bus at the device registration point. This also follows
> > > the way the PCI devices are being managed, see pci_device_add().
> > >
> > > If it turns out that this is an acceptable solution, we probably also
> > > want the changes for stable, but I am not sure if it applies without conflicts.
> > >
> > > The series is based on v5.6-rc7.
> > >
> >
> > Hi Ulf,
> >
> > Since i.MXQM SMMU related code still not upstream yet, so I apply your
> > patches on our internal Linux branch based on v5.4.24, and find it do not work
> > on my side. Maybe for platform core drivers, there is a gap between v5.4.24
> > and v5.6-rc7 which has the impact.
> > I will try to put our SMMU related code into v5.6-rc7, then do the test again.
> >
> >
>
> Hi Ulf,
>
> On the latest Linux-next branch, the top commit 89295c59c1f063b533d071ca49d0fa0c0783ca6f (tag: next-20200326), after add your two patches, I just add the simple debug code as following in the /driver/mmc/core/queue.c, but seems still not work as our expect, logically, it should work, so can you or anyone test on other platform? This seems weird.

You are right, this doesn't work for platform devices being added
through the OF path.

In other words, of_platform_device_create_pdata() manually allocates
the platform device and assigns it the &platform_bus_type, but without
calling platform_device_add().

For amba, it works fine, as in that OF path, amba_device_add() is called. Hmm.

I re-spin this, to address the problem. Perhaps we simply need to use
the ->probe() path.

Kind regards
Uffe

>
> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
> index 25bee3daf9e2..f091280f7ffb 100644
> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -403,6 +403,13 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
>                 blk_queue_max_segment_size(mq->queue,
>                         round_down(host->max_seg_size, block_size));
>
> +       pr_err("###### the max segment size is %d\n", queue_max_segment_size(mq->queue));
> +       if (host->parent->dma_parms) {
> +                      pr_err("######### the dma parms has value\n");
> +       } else if (!(host->parent->dma_parms)) {
> +                      pr_err("######## the dma parms is zero!!\n");
> +       }
> +
>         dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
>
>         INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
>
> Here is the log I got when system run, even after your patch, the dev->dma_parms is still NULL.
> [    0.989853] mmc0: new HS400 MMC card at address 0001
> [    0.995708] sdhci-esdhc-imx 30b50000.mmc: Got CD GPIO
> [    0.999374] ###### the max segment size is 65024
> [    1.008594] ######## the dma parms is zero!!
> [    1.012875] mmcblk0: mmc0:0001 IB2932 29.2 GiB
> [    1.017569] ###### the max segment size is 65024
> [    1.022195] ######## the dma parms is zero!!
> [    1.026479] mmcblk0boot0: mmc0:0001 IB2932 partition 1 4.00 MiB
> [    1.032541] ###### the max segment size is 65024
> [    1.035198] mmc1: SDHCI controller on 30b50000.mmc [30b50000.mmc] using ADMA
> [    1.037169] ######## the dma parms is zero!!
> [    1.048493] mmcblk0boot1: mmc0:0001 IB2932 partition 2 4.00 MiB
> [    1.054531] mmcblk0rpmb: mmc0:0001 IB2932 partition 3 4.00 MiB, chardev (234:0)
>
>
> Regards
> Haibo Chen
> > Best Regards
> > Haibo Chen
> >
> > > Kind regards
> > > Ulf Hansson
> > >
> > > Ulf Hansson (2):
> > >   driver core: platform: Initialize dma_parms for platform devices
> > >   amba: Initialize dma_parms for amba devices
> > >
> > >  drivers/amba/bus.c              | 2 ++
> > >  drivers/base/platform.c         | 1 +
> > >  include/linux/amba/bus.h        | 1 +
> > >  include/linux/platform_device.h | 1 +
> > >  4 files changed, 5 insertions(+)
> > >
> > > --
> > > 2.20.1
>

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
  2020-03-27 15:34     ` Ulf Hansson
@ 2020-03-27 19:15       ` Robin Murphy
  0 siblings, 0 replies; 13+ messages in thread
From: Robin Murphy @ 2020-03-27 19:15 UTC (permalink / raw)
  To: Ulf Hansson, BOUGH CHEN
  Cc: Arnd Bergmann, Rafael J . Wysocki, Greg Kroah-Hartman,
	Linus Walleij, Russell King, linux-kernel, Vinod Koul,
	linux-arm-kernel, dmaengine, Christoph Hellwig, Ludovic Barre

On 2020-03-27 3:34 pm, Ulf Hansson wrote:
> On Fri, 27 Mar 2020 at 04:02, BOUGH CHEN <haibo.chen@nxp.com> wrote:
>>
>>
>>> -----Original Message-----
>>> From: BOUGH CHEN
>>> Sent: 2020年3月26日 12:41
>>> To: Ulf Hansson <ulf.hansson@linaro.org>; Greg Kroah-Hartman
>>> <gregkh@linuxfoundation.org>; Rafael J . Wysocki <rafael@kernel.org>;
>>> linux-kernel@vger.kernel.org
>>> Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
>>> Russell King <linux@armlinux.org.uk>; Linus Walleij <linus.walleij@linaro.org>;
>>> Vinod Koul <vkoul@kernel.org>; Ludovic Barre <ludovic.barre@st.com>;
>>> linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org
>>> Subject: RE: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level
>>>
>>>> -----Original Message-----
>>>> From: Ulf Hansson <ulf.hansson@linaro.org>
>>>> Sent: 2020年3月25日 19:34
>>>> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rafael J .
>>>> Wysocki <rafael@kernel.org>; linux-kernel@vger.kernel.org
>>>> Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
>>>> Russell King <linux@armlinux.org.uk>; Linus Walleij
>>>> <linus.walleij@linaro.org>; Vinod Koul <vkoul@kernel.org>; BOUGH CHEN
>>>> <haibo.chen@nxp.com>; Ludovic Barre <ludovic.barre@st.com>;
>>>> linux-arm-kernel@lists.infradead.org; dmaengine@vger.kernel.org; Ulf
>>>> Hansson <ulf.hansson@linaro.org>
>>>> Subject: [PATCH 0/2] amba/platform: Initialize dma_parms at the bus
>>>> level
>>>>
>>>> It's currently the amba/platform driver's responsibility to initialize
>>>> the pointer, dma_parms, for its corresponding struct device. The
>>>> benefit with this approach allows us to avoid the initialization and
>>>> to not waste memory for the struct device_dma_parameters, as this can
>>>> be decided on a case by case basis.
>>>>
>>>> However, it has turned out that this approach is not very practical.
>>>> Not only does it lead to open coding, but also to real errors. In
>>>> principle callers of
>>>> dma_set_max_seg_size() doesn't check the error code, but just assumes
>>>> it succeeds.
>>>>
>>>> For these reasons, this series initializes the dma_parms from the
>>>> amba/platform bus at the device registration point. This also follows
>>>> the way the PCI devices are being managed, see pci_device_add().
>>>>
>>>> If it turns out that this is an acceptable solution, we probably also
>>>> want the changes for stable, but I am not sure if it applies without conflicts.
>>>>
>>>> The series is based on v5.6-rc7.
>>>>
>>>
>>> Hi Ulf,
>>>
>>> Since i.MXQM SMMU related code still not upstream yet, so I apply your
>>> patches on our internal Linux branch based on v5.4.24, and find it do not work
>>> on my side. Maybe for platform core drivers, there is a gap between v5.4.24
>>> and v5.6-rc7 which has the impact.
>>> I will try to put our SMMU related code into v5.6-rc7, then do the test again.
>>>
>>>
>>
>> Hi Ulf,
>>
>> On the latest Linux-next branch, the top commit 89295c59c1f063b533d071ca49d0fa0c0783ca6f (tag: next-20200326), after add your two patches, I just add the simple debug code as following in the /driver/mmc/core/queue.c, but seems still not work as our expect, logically, it should work, so can you or anyone test on other platform? This seems weird.
> 
> You are right, this doesn't work for platform devices being added
> through the OF path.
> 
> In other words, of_platform_device_create_pdata() manually allocates
> the platform device and assigns it the &platform_bus_type, but without
> calling platform_device_add().
> 
> For amba, it works fine, as in that OF path, amba_device_add() is called. Hmm.
> 
> I re-spin this, to address the problem. Perhaps we simply need to use
> the ->probe() path.

FWIW we already have setup_pdev_dma_masks(), so it might be logical to 
include dma_parms in there too.

Robin.

> 
> Kind regards
> Uffe
> 
>>
>> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
>> index 25bee3daf9e2..f091280f7ffb 100644
>> --- a/drivers/mmc/core/queue.c
>> +++ b/drivers/mmc/core/queue.c
>> @@ -403,6 +403,13 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
>>                  blk_queue_max_segment_size(mq->queue,
>>                          round_down(host->max_seg_size, block_size));
>>
>> +       pr_err("###### the max segment size is %d\n", queue_max_segment_size(mq->queue));
>> +       if (host->parent->dma_parms) {
>> +                      pr_err("######### the dma parms has value\n");
>> +       } else if (!(host->parent->dma_parms)) {
>> +                      pr_err("######## the dma parms is zero!!\n");
>> +       }
>> +
>>          dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
>>
>>          INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
>>
>> Here is the log I got when system run, even after your patch, the dev->dma_parms is still NULL.
>> [    0.989853] mmc0: new HS400 MMC card at address 0001
>> [    0.995708] sdhci-esdhc-imx 30b50000.mmc: Got CD GPIO
>> [    0.999374] ###### the max segment size is 65024
>> [    1.008594] ######## the dma parms is zero!!
>> [    1.012875] mmcblk0: mmc0:0001 IB2932 29.2 GiB
>> [    1.017569] ###### the max segment size is 65024
>> [    1.022195] ######## the dma parms is zero!!
>> [    1.026479] mmcblk0boot0: mmc0:0001 IB2932 partition 1 4.00 MiB
>> [    1.032541] ###### the max segment size is 65024
>> [    1.035198] mmc1: SDHCI controller on 30b50000.mmc [30b50000.mmc] using ADMA
>> [    1.037169] ######## the dma parms is zero!!
>> [    1.048493] mmcblk0boot1: mmc0:0001 IB2932 partition 2 4.00 MiB
>> [    1.054531] mmcblk0rpmb: mmc0:0001 IB2932 partition 3 4.00 MiB, chardev (234:0)
>>
>>
>> Regards
>> Haibo Chen
>>> Best Regards
>>> Haibo Chen
>>>
>>>> Kind regards
>>>> Ulf Hansson
>>>>
>>>> Ulf Hansson (2):
>>>>    driver core: platform: Initialize dma_parms for platform devices
>>>>    amba: Initialize dma_parms for amba devices
>>>>
>>>>   drivers/amba/bus.c              | 2 ++
>>>>   drivers/base/platform.c         | 1 +
>>>>   include/linux/amba/bus.h        | 1 +
>>>>   include/linux/platform_device.h | 1 +
>>>>   4 files changed, 5 insertions(+)
>>>>
>>>> --
>>>> 2.20.1
>>
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, back to index

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-25 11:34 [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level Ulf Hansson
2020-03-25 11:34 ` [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Ulf Hansson
2020-03-25 15:23   ` Ludovic BARRE
2020-03-26 11:01   ` Linus Walleij
2020-03-26 11:06   ` Arnd Bergmann
2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson
2020-03-25 15:24   ` Ludovic BARRE
2020-03-26 11:02   ` Linus Walleij
2020-03-26 11:07   ` Arnd Bergmann
2020-03-26  4:41 ` [PATCH 0/2] amba/platform: Initialize dma_parms at the bus level BOUGH CHEN
2020-03-27  3:02   ` BOUGH CHEN
2020-03-27 15:34     ` Ulf Hansson
2020-03-27 19:15       ` Robin Murphy

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