From: Ludovic BARRE <ludovic.barre@st.com> 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>, Haibo Chen <haibo.chen@nxp.com>, <linux-arm-kernel@lists.infradead.org>, <dmaengine@vger.kernel.org>, <stable@vger.kernel.org> Subject: Re: [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Date: Wed, 25 Mar 2020 16:23:46 +0100 [thread overview] Message-ID: <598b3a55-0321-d7ea-8758-edaba5d5cb2c@st.com> (raw) In-Reply-To: <20200325113407.26996-2-ulf.hansson@linaro.org> 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; > >
WARNING: multiple messages have this Message-ID (diff)
From: Ludovic BARRE <ludovic.barre@st.com> 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>, Linus Walleij <linus.walleij@linaro.org>, Russell King <linux@armlinux.org.uk>, Haibo Chen <haibo.chen@nxp.com>, Vinod Koul <vkoul@kernel.org>, stable@vger.kernel.org, dmaengine@vger.kernel.org, Christoph Hellwig <hch@lst.de>, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 1/2] driver core: platform: Initialize dma_parms for platform devices Date: Wed, 25 Mar 2020 16:23:46 +0100 [thread overview] Message-ID: <598b3a55-0321-d7ea-8758-edaba5d5cb2c@st.com> (raw) In-Reply-To: <20200325113407.26996-2-ulf.hansson@linaro.org> 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; > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-03-25 15:24 UTC|newest] Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top 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 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 15:23 ` Ludovic BARRE [this message] 2020-03-25 15:23 ` Ludovic BARRE 2020-03-26 11:01 ` Linus Walleij 2020-03-26 11:01 ` Linus Walleij 2020-03-26 11:06 ` Arnd Bergmann 2020-03-26 11:06 ` Arnd Bergmann 2020-03-27 15:03 ` Sasha Levin 2020-03-25 11:34 ` [PATCH 2/2] amba: Initialize dma_parms for amba devices Ulf Hansson 2020-03-25 11:34 ` Ulf Hansson 2020-03-25 15:24 ` Ludovic BARRE 2020-03-25 15:24 ` Ludovic BARRE 2020-03-26 11:02 ` Linus Walleij 2020-03-26 11:02 ` Linus Walleij 2020-03-26 11:07 ` Arnd Bergmann 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 2020-03-26 4:41 ` BOUGH CHEN 2020-03-27 3:02 ` BOUGH CHEN 2020-03-27 3:02 ` BOUGH CHEN 2020-03-27 15:34 ` Ulf Hansson 2020-03-27 15:34 ` Ulf Hansson 2020-03-27 19:15 ` Robin Murphy 2020-03-27 19:15 ` Robin Murphy 2020-03-31 18:08 ` Ulf Hansson 2020-03-31 18:08 ` Ulf Hansson
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