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;
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;
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
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
Hi
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This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all
The bot has tested the following trees: v5.5.11, v5.4.27, v4.19.112, v4.14.174, v4.9.217, v4.4.217.
v5.5.11: Build OK! v5.4.27: Build OK! v4.19.112: Failed to apply! Possible dependencies: cdfee5623290 ("driver core: initialize a default DMA mask for platform device") e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation")
v4.14.174: Failed to apply! Possible dependencies: 186c446f4b84 ("media: arch: sh: migor: Use new renesas-ceu camera driver") 1a3c230b4151 ("media: arch: sh: ms7724se: Use new renesas-ceu camera driver") 39fb993038e1 ("media: arch: sh: ap325rxa: Use new renesas-ceu camera driver") b12c8a70643f ("m68k: Set default dma mask for platform devices") c2f9b05fd5c1 ("media: arch: sh: ecovec: Use new renesas-ceu camera driver") cdfee5623290 ("driver core: initialize a default DMA mask for platform device") e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation") f3590dc32974 ("media: arch: sh: kfr2r09: Use new renesas-ceu camera driver")
v4.9.217: Failed to apply! Possible dependencies: 186c446f4b84 ("media: arch: sh: migor: Use new renesas-ceu camera driver") 1a3c230b4151 ("media: arch: sh: ms7724se: Use new renesas-ceu camera driver") 39fb993038e1 ("media: arch: sh: ap325rxa: Use new renesas-ceu camera driver") 8fd708157a59 ("Input: tsc2007 - move header file out of I2C realm") b12c8a70643f ("m68k: Set default dma mask for platform devices") c2f9b05fd5c1 ("media: arch: sh: ecovec: Use new renesas-ceu camera driver") cdfee5623290 ("driver core: initialize a default DMA mask for platform device") e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation") f14434040ce0 ("Input: tsc2007 - add iio interface to read external ADC input and temperature") f3590dc32974 ("media: arch: sh: kfr2r09: Use new renesas-ceu camera driver")
v4.4.217: Failed to apply! Possible dependencies: 166dd7d3fbf2 ("powerpc/64: Move MMU backend selection out of platform code") 340f3039acd6 ("m68k: convert to dma_map_ops") 3808a88985b4 ("powerpc: Move FW feature probing out of pseries probe()") 406b0b6ae3fc ("powerpc/64: Move 64-bit probe_machine() to later in the boot process") 565713840445 ("powerpc: Move 32-bit probe() machine to later in the boot process") 5d31a96e6c01 ("powerpc/livepatch: Add livepatch stack to struct thread_info") 63c254a50104 ("powerpc: Add comment explaining the purpose of setup_kdump_trampoline()") b12c8a70643f ("m68k: Set default dma mask for platform devices") b1923caa6e64 ("powerpc: Merge 32-bit and 64-bit setup_arch()") cdfee5623290 ("driver core: initialize a default DMA mask for platform device") da6a97bf12d5 ("powerpc: Move epapr_paravirt_early_init() to early_init_devtree()") e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation") f63e6d898760 ("powerpc/livepatch: Add livepatch header")
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
linux-stable-mirror@lists.linaro.org
-
Arnd Bergmann -
Linus Walleij -
Ludovic BARRE -
Sasha Levin -
Ulf Hansson