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