From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Cameron Subject: Re: [PATCH] staging iio: Replace kmalloc with local variable Date: Tue, 07 Jun 2011 14:54:05 +0100 Message-ID: <4DEE2D7D.6070506@cam.ac.uk> References: <1307450354.1516.23.camel@anish-desktop> <4DEE20E7.4020008@cam.ac.uk> <20110607134135.GD15795@trinity.fluff.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110607134135.GD15795-SMNkleLxa3Z6Wcw2j4pizdi2O/JbrIOy@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ben Dooks Cc: anish , gregkh-l3A5Bk7waGM@public.gmane.org, manuel.stahl-GeUHRtUQU7nSyEMIgutvibNAH6kLmebB@public.gmane.org, lucas.demarchi-Y3ZbgMPKUGA34EUeqzHoZw@public.gmane.org, devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux I2C List-Id: linux-i2c@vger.kernel.org On 06/07/11 14:41, Ben Dooks wrote: > On Tue, Jun 07, 2011 at 02:00:23PM +0100, Jonathan Cameron wrote: >> On 06/07/11 13:39, anish wrote: >>> From: anish kumar >>> >>> replaced kmalloc with local variable as I2C(in this case) doesn't require >>> kmalloc memory it can do with stack memory. >> I've cc'd linux-i2c just to check I'm right about the whole i2c doesn't need >> dma safe buffers bit... > > No, it is down to the i2c driver, and from recollection dma from stack is > not recommended, due to things like cache line alignment. Please do not > do this. Then lets drop this. Sorry Anish, seems I led you down the garden path. I'll check all my i2c drivers don't do this... > >>> Signed-off-by: anish kumar >> Acked-by: Jonathan Cameron >>> --- >>> drivers/staging/iio/adc/max1363_core.c | 5 +---- >>> 1 files changed, 1 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/staging/iio/adc/max1363_core.c b/drivers/staging/iio/adc/max1363_core.c >>> index 1037087..9462230 100644 >>> --- a/drivers/staging/iio/adc/max1363_core.c >>> +++ b/drivers/staging/iio/adc/max1363_core.c >>> @@ -207,15 +207,12 @@ static int max1363_write_basic_config(struct i2c_client *client, >>> unsigned char d2) >>> { >>> int ret; >>> - u8 *tx_buf = kmalloc(2, GFP_KERNEL); >>> + u8 tx_buf[2]; >>> >>> - if (!tx_buf) >>> - return -ENOMEM; >>> tx_buf[0] = d1; >>> tx_buf[1] = d2; >>> >>> ret = i2c_master_send(client, tx_buf, 2); >>> - kfree(tx_buf); >>> >>> return (ret > 0) ? 0 : ret; >>> } >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in >> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >