From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [alsa-devel] [PATCH v2 3/5] ASoC: generic-dmaengine-pcm: Prepare formats mask for valid physical sample sizes Date: Wed, 02 Jul 2014 16:10:09 +0200 Message-ID: <53B412C1.20406@metafoo.de> References: <1404307763-30557-1-git-send-email-peter.ujfalusi@ti.com> <1404307763-30557-4-git-send-email-peter.ujfalusi@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Takashi Iwai , Peter Ujfalusi Cc: alsa-devel@alsa-project.org, vinod.koul@intel.com, nsekhar@ti.com, Liam Girdwood , linux-kernel@vger.kernel.org, joelf@ti.com, Mark Brown , dmaengine@vger.kernel.org, dan.j.williams@intel.com List-Id: alsa-devel@alsa-project.org On 07/02/2014 03:47 PM, Takashi Iwai wrote: [...] >> + /* >> + * Prepare formats mask for valid/allowed sample types. If the dma does >> + * not have support for the given physical word size, it needs to be >> + * masked out so user space can not use the format which produces >> + * corrupted audio. >> + * In case the dma driver does not implement the slave_caps the default >> + * assumption is that it supports 1, 2 and 4 bytes widths. >> + */ >> + for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) { >> + int bits = snd_pcm_format_physical_width(i); > > Better to add a negative value check. Some formats return -EINVAL. > So what should we do with those formats? Not support them? >> + >> + /* Enable only samples with DMA supported physical widths */ >> + if (addr_widths & BIT(bits / 8)) > > Just nitpicking: Using BIT() for 32bit int isn't always a wise choice > since BIT() is defined as unsigned long. This is a generic problem, > though, as we see many codes using BIT() wrongly (and thus get > compiler warnings on 64bit machines). We should introduce a new macro > for 32bit int...