From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH v3 1/4] i2c: add helpers to ease DMA handling Date: Wed, 16 Aug 2017 16:51:33 +0200 Message-ID: References: <20170718102339.28726-1-wsa+renesas@sang-engineering.com> <20170718102339.28726-2-wsa+renesas@sang-engineering.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20170718102339.28726-2-wsa+renesas@sang-engineering.com> Sender: linux-renesas-soc-owner@vger.kernel.org To: Wolfram Sang Cc: Linux I2C , Linux-Renesas , Linux Media Mailing List , "linux-input@vger.kernel.org" , linux-iio@vger.kernel.org, ALSA Development Mailing List , "linux-kernel@vger.kernel.org" List-Id: alsa-devel@alsa-project.org Hi Wolfram, On Tue, Jul 18, 2017 at 12:23 PM, Wolfram Sang wrote: > One helper checks if DMA is suitable and optionally creates a bounce > buffer, if not. The other function returns the bounce buffer and makes > sure the data is properly copied back to the message. > > Signed-off-by: Wolfram Sang > --- > Changes since v2: > > * rebased to v4.13-rc1 > * helper functions are not inlined anymore but moved to i2c core > * __must_check has been added to the buffer check helper > * the release function has been renamed to contain 'dma' as well Right: drivers/i2c/i2c-core-base.c:2310:15: error: 'i2c_release_bounce_buf' undeclared here (not in a function) EXPORT_SYMBOL_GPL(i2c_release_bounce_buf); > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > +/** > + * i2c_release_bounce_buf - copy data back from bounce buffer and release it ^^^^^^^^^^^^^^^^^^^^^^ > + * @msg: the message to be copied back to > + * @bounce_buf: the bounce buffer obtained from i2c_check_msg_for_dma(). > + * May be NULL. > + */ > +void i2c_release_dma_bounce_buf(struct i2c_msg *msg, u8 *bounce_buf) > +{ > + if (!bounce_buf) > + return; > + > + if (msg->flags & I2C_M_RD) > + memcpy(msg->buf, bounce_buf, msg->len); > + > + kfree(bounce_buf); > +} > +EXPORT_SYMBOL_GPL(i2c_release_bounce_buf); ^^^^^^^^^^^^^^^^^^^^^^ Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds