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amba: Initialize dma_parms for amba devices 

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().

Cc: <stable@vger.kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
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/20200325113407.26996-3-ulf.hansson@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ulf Hansson 2020-03-25 12:34:07 +01:00 committed by Greg Kroah-Hartman
parent 7c8978c083
commit 5caf6102e3
2 changed files with 3 additions and 0 deletions
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2
drivers/amba/bus.c
View File

@ -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;

1
include/linux/amba/bus.h
View File

@ -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;