From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Mon, 15 Oct 2018 00:36:36 +0200 Subject: [PATCH] mmc: tmio: simplify the DMA mode test In-Reply-To: <1539356588-18191-1-git-send-email-yamada.masahiro@socionext.com> References: <1539356588-18191-1-git-send-email-yamada.masahiro@socionext.com> Message-ID: <20181014223636.GH3260@kunai> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Oct 13, 2018 at 12:03:08AM +0900, Masahiro Yamada wrote: > host->chan_{rx,tx} represents the DMA capability of the platform. > Even if DMA is supported, there are cases where we want to use PIO, > for example, data length is short enough as commit 5f52c3552946 > ("mmc: tmio: use PIO for short transfers") mentioned. > > Regarding the hardware control flow, we are interested in whether DMA > is currently enabled or not, instead of whether the platform has the > DMA capability. > > Hence, the several conditionals in tmio_mmc_core.c end up with > checking host->chan_{rx,tx} and !host->force_pio. This is not nice. > > Let's flip the flag host->force_pio into host->dma_on. > > host->dma_on represents whether the DMA is currently enabled or not. > This flag is set false in the beginning of each command, then should > be set true by tmio_mmc_start_dma() when the DMA is turned on. > > Signed-off-by: Masahiro Yamada I like it. Much easier to read! Reviewed-by: Wolfram Sang Also here, I'd like to test this on Monday on some more devices. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: