From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter.Chen@freescale.com (Peter Chen) Date: Wed, 16 Jul 2014 11:58:14 +0000 Subject: [PATCH v3 07/12] usb: chipidea: add a usb2 driver for ci13xxx In-Reply-To: <5615007.cNNjmu3rBK@wuerfel> References: <1405499166-6726-1-git-send-email-antoine.tenart@free-electrons.com> <42036198.zWkqnus6xa@wuerfel> <20140716091533.GB28151@kwain> <5615007.cNNjmu3rBK@wuerfel> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > > > > Some people wanted the possibility to set the DMA mask as this USB2 CI > > driver does not do specific Berlin operation and can be reused later. > > I don't particularly need to call dma_coerce_mask_and_coherent() in my > > case, as far as I know. > > Ok, just remove the call then and rely on the default mask. > > > They can maybe give the restrictions they might want to put on the DMA > > mask. > > If the restriction is from the bus, it should get handled automatically > by the device probe as long as the correct dma-ranges property is there > (though we have a small bug there at the moment). If there is a variation > of ci13xxx that can't do 32-bit DMA, that should use a different > compatible string and pass a fixed mask into dma_set_mask_and_coherent() > based on the device. > Correct me if my below understanding is wrong please. For three chipidea users: user_a: don't need dma mask user_b: dma mask value is dma_mask_b user_c: dma mask value is dma_mask_c We don't need to call dma_coerce_mask_and_coherent() at generic chipidea glue driver, and set dma-ranges as dma_mask_b at user_b's dts, and set dma-ranges as dma_mask_c at user_c's dts. Peter