From 0f6a928d035b82c0b3aa387d510a73f3e6dbf8e3 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 6 Feb 2014 13:25:40 +0200 Subject: [PATCH] acpi-dma: convert to return error code when asked for channel Currently acpi_dma_request_slave_chan_by_index() and acpi_dma_request_slave_chan_by_name() return only requested channel or NULL. This patch converts them to return appropriate error code instead of NULL in case of unsuccessfull request. Signed-off-by: Andy Shevchenko Acked-by: Mika Westerberg Signed-off-by: Vinod Koul --- drivers/dma/acpi-dma.c | 15 ++++++++------- drivers/dma/dmaengine.c | 9 ++------- include/linux/acpi_dma.h | 5 +++-- 3 files changed, 13 insertions(+), 16 deletions(-) diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index 1fda371af4b7..de361a156b34 100644 --- a/drivers/dma/acpi-dma.c +++ b/drivers/dma/acpi-dma.c @@ -13,6 +13,7 @@ */ #include +#include #include #include #include @@ -343,7 +344,7 @@ static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) * @index: index of FixedDMA descriptor for @dev * * Return: - * Pointer to appropriate dma channel on success or NULL on error. + * Pointer to appropriate dma channel on success or an error pointer. */ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, size_t index) @@ -358,10 +359,10 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, /* Check if the device was enumerated by ACPI */ if (!dev || !ACPI_HANDLE(dev)) - return NULL; + return ERR_PTR(-ENODEV); if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev)) - return NULL; + return ERR_PTR(-ENODEV); memset(&pdata, 0, sizeof(pdata)); pdata.index = index; @@ -376,7 +377,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, acpi_dev_free_resource_list(&resource_list); if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) - return NULL; + return ERR_PTR(-ENODEV); mutex_lock(&acpi_dma_lock); @@ -399,7 +400,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, } mutex_unlock(&acpi_dma_lock); - return chan; + return chan ? chan : ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); @@ -413,7 +414,7 @@ EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); * the first FixedDMA descriptor is TX and second is RX. * * Return: - * Pointer to appropriate dma channel on success or NULL on error. + * Pointer to appropriate dma channel on success or an error pointer. */ struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, const char *name) @@ -425,7 +426,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, else if (!strcmp(name, "rx")) index = 1; else - return NULL; + return ERR_PTR(-ENODEV); return acpi_dma_request_slave_chan_by_index(dev, index); } diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index ed610b497518..a886713937fd 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -627,18 +627,13 @@ EXPORT_SYMBOL_GPL(__dma_request_channel); struct dma_chan *dma_request_slave_channel_reason(struct device *dev, const char *name) { - struct dma_chan *chan; - /* If device-tree is present get slave info from here */ if (dev->of_node) return of_dma_request_slave_channel(dev->of_node, name); /* If device was enumerated by ACPI get slave info from here */ - if (ACPI_HANDLE(dev)) { - chan = acpi_dma_request_slave_chan_by_name(dev, name); - if (chan) - return chan; - } + if (ACPI_HANDLE(dev)) + return acpi_dma_request_slave_chan_by_name(dev, name); return ERR_PTR(-ENODEV); } diff --git a/include/linux/acpi_dma.h b/include/linux/acpi_dma.h index fb0298082916..329436d38e66 100644 --- a/include/linux/acpi_dma.h +++ b/include/linux/acpi_dma.h @@ -16,6 +16,7 @@ #include #include +#include #include /** @@ -103,12 +104,12 @@ static inline void devm_acpi_dma_controller_free(struct device *dev) static inline struct dma_chan *acpi_dma_request_slave_chan_by_index( struct device *dev, size_t index) { - return NULL; + return ERR_PTR(-ENODEV); } static inline struct dma_chan *acpi_dma_request_slave_chan_by_name( struct device *dev, const char *name) { - return NULL; + return ERR_PTR(-ENODEV); } #define acpi_dma_simple_xlate NULL -- 2.20.1