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* patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing
@ 2020-03-26 14:58 gregkh
  2020-03-31 18:43 ` Ulf Hansson
  0 siblings, 1 reply; 5+ messages in thread
From: gregkh @ 2020-03-26 14:58 UTC (permalink / raw)
  To: ulf.hansson, arnd, gregkh, hch, linus.walleij, ludovic.barre, stable


This is a note to let you know that I've just added the patch titled

    driver core: platform: Initialize dma_parms for platform devices

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the char-misc-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


From 7c8978c0837d40c302f5e90d24c298d9ca9fc097 Mon Sep 17 00:00:00 2001
From: Ulf Hansson <ulf.hansson@linaro.org>
Date: Wed, 25 Mar 2020 12:34:06 +0100
Subject: driver core: platform: Initialize dma_parms for platform devices

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().

Cc: <stable@vger.kernel.org>
Suggested-by: Christoph Hellwig <hch@lst.de>
Tested-by: Ludovic Barre <ludovic.barre@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200325113407.26996-2-ulf.hansson@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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;
 
-- 
2.26.0



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing
  2020-03-26 14:58 patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing gregkh
@ 2020-03-31 18:43 ` Ulf Hansson
  2020-04-01  6:07   ` Greg Kroah-Hartman
  0 siblings, 1 reply; 5+ messages in thread
From: Ulf Hansson @ 2020-03-31 18:43 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Arnd Bergmann, Christoph Hellwig, Linus Walleij, Ludovic Barre, # 4.0+

On Thu, 26 Mar 2020 at 15:58, <gregkh@linuxfoundation.org> wrote:
>
>
> This is a note to let you know that I've just added the patch titled
>
>     driver core: platform: Initialize dma_parms for platform devices
>
> to my char-misc git tree which can be found at
>     git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> in the char-misc-testing branch.
>
> The patch will show up in the next release of the linux-next tree
> (usually sometime within the next 24 hours during the week.)
>
> The patch will be merged to the char-misc-next branch sometime soon,
> after it passes testing, and the merge window is open.
>
> If you have any questions about this process, please let me know.

Greg, would you mind dropping this one and the other patch for the amba bus?

I just sent out a new version (v2), addressing an issue for the
platform device when used for OF based platforms.

If you prefer to not rebase/drop patches from your branch, I can send
an incremental change on top instead, whatever you prefer.

Kind regards
Uffe

>
>
> From 7c8978c0837d40c302f5e90d24c298d9ca9fc097 Mon Sep 17 00:00:00 2001
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Date: Wed, 25 Mar 2020 12:34:06 +0100
> Subject: driver core: platform: Initialize dma_parms for platform devices
>
> 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().
>
> Cc: <stable@vger.kernel.org>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Tested-by: Ludovic Barre <ludovic.barre@st.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Link: https://lore.kernel.org/r/20200325113407.26996-2-ulf.hansson@linaro.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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;
>
> --
> 2.26.0
>
>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing
  2020-03-31 18:43 ` Ulf Hansson
@ 2020-04-01  6:07   ` Greg Kroah-Hartman
  2020-04-01  8:12     ` Ulf Hansson
  0 siblings, 1 reply; 5+ messages in thread
From: Greg Kroah-Hartman @ 2020-04-01  6:07 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Arnd Bergmann, Christoph Hellwig, Linus Walleij, Ludovic Barre, # 4.0+

On Tue, Mar 31, 2020 at 08:43:25PM +0200, Ulf Hansson wrote:
> On Thu, 26 Mar 2020 at 15:58, <gregkh@linuxfoundation.org> wrote:
> >
> >
> > This is a note to let you know that I've just added the patch titled
> >
> >     driver core: platform: Initialize dma_parms for platform devices
> >
> > to my char-misc git tree which can be found at
> >     git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> > in the char-misc-testing branch.
> >
> > The patch will show up in the next release of the linux-next tree
> > (usually sometime within the next 24 hours during the week.)
> >
> > The patch will be merged to the char-misc-next branch sometime soon,
> > after it passes testing, and the merge window is open.
> >
> > If you have any questions about this process, please let me know.
> 
> Greg, would you mind dropping this one and the other patch for the amba bus?
> 
> I just sent out a new version (v2), addressing an issue for the
> platform device when used for OF based platforms.
> 
> If you prefer to not rebase/drop patches from your branch, I can send
> an incremental change on top instead, whatever you prefer.

I will just revert these and then send it all on to Linus later today.
That way you can have the longer development cycle for better testing.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing
  2020-04-01  6:07   ` Greg Kroah-Hartman
@ 2020-04-01  8:12     ` Ulf Hansson
  2020-04-01  8:21       ` Greg Kroah-Hartman
  0 siblings, 1 reply; 5+ messages in thread
From: Ulf Hansson @ 2020-04-01  8:12 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Arnd Bergmann, Christoph Hellwig, Linus Walleij, Ludovic Barre, # 4.0+

On Wed, 1 Apr 2020 at 08:07, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Mar 31, 2020 at 08:43:25PM +0200, Ulf Hansson wrote:
> > On Thu, 26 Mar 2020 at 15:58, <gregkh@linuxfoundation.org> wrote:
> > >
> > >
> > > This is a note to let you know that I've just added the patch titled
> > >
> > >     driver core: platform: Initialize dma_parms for platform devices
> > >
> > > to my char-misc git tree which can be found at
> > >     git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> > > in the char-misc-testing branch.
> > >
> > > The patch will show up in the next release of the linux-next tree
> > > (usually sometime within the next 24 hours during the week.)
> > >
> > > The patch will be merged to the char-misc-next branch sometime soon,
> > > after it passes testing, and the merge window is open.
> > >
> > > If you have any questions about this process, please let me know.
> >
> > Greg, would you mind dropping this one and the other patch for the amba bus?
> >
> > I just sent out a new version (v2), addressing an issue for the
> > platform device when used for OF based platforms.
> >
> > If you prefer to not rebase/drop patches from your branch, I can send
> > an incremental change on top instead, whatever you prefer.
>
> I will just revert these and then send it all on to Linus later today.
> That way you can have the longer development cycle for better testing.

Alright!

Actually, reverting wasn't really necessary as the patches didn't
break anything, just that v1 did fix the complete range of the
problems.

Kind regards
Uffe

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing
  2020-04-01  8:12     ` Ulf Hansson
@ 2020-04-01  8:21       ` Greg Kroah-Hartman
  0 siblings, 0 replies; 5+ messages in thread
From: Greg Kroah-Hartman @ 2020-04-01  8:21 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Arnd Bergmann, Christoph Hellwig, Linus Walleij, Ludovic Barre, # 4.0+

On Wed, Apr 01, 2020 at 10:12:28AM +0200, Ulf Hansson wrote:
> On Wed, 1 Apr 2020 at 08:07, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Tue, Mar 31, 2020 at 08:43:25PM +0200, Ulf Hansson wrote:
> > > On Thu, 26 Mar 2020 at 15:58, <gregkh@linuxfoundation.org> wrote:
> > > >
> > > >
> > > > This is a note to let you know that I've just added the patch titled
> > > >
> > > >     driver core: platform: Initialize dma_parms for platform devices
> > > >
> > > > to my char-misc git tree which can be found at
> > > >     git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> > > > in the char-misc-testing branch.
> > > >
> > > > The patch will show up in the next release of the linux-next tree
> > > > (usually sometime within the next 24 hours during the week.)
> > > >
> > > > The patch will be merged to the char-misc-next branch sometime soon,
> > > > after it passes testing, and the merge window is open.
> > > >
> > > > If you have any questions about this process, please let me know.
> > >
> > > Greg, would you mind dropping this one and the other patch for the amba bus?
> > >
> > > I just sent out a new version (v2), addressing an issue for the
> > > platform device when used for OF based platforms.
> > >
> > > If you prefer to not rebase/drop patches from your branch, I can send
> > > an incremental change on top instead, whatever you prefer.
> >
> > I will just revert these and then send it all on to Linus later today.
> > That way you can have the longer development cycle for better testing.
> 
> Alright!
> 
> Actually, reverting wasn't really necessary as the patches didn't
> break anything, just that v1 did fix the complete range of the
> problems.

This late in the cycle, reverting is probably best :)

^ permalink raw reply	[flat|nested] 5+ messages in thread

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Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-26 14:58 patch "driver core: platform: Initialize dma_parms for platform devices" added to char-misc-testing gregkh
2020-03-31 18:43 ` Ulf Hansson
2020-04-01  6:07   ` Greg Kroah-Hartman
2020-04-01  8:12     ` Ulf Hansson
2020-04-01  8:21       ` Greg Kroah-Hartman

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