From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laxman Dewangan Subject: Re: [PATCH V3 2/4] soc/tegra: pmc: Correct type of variable for tegra_pmc_readl() Date: Thu, 5 May 2016 18:05:07 +0530 Message-ID: <572B3DFB.3070604@nvidia.com> References: <1462361973-27990-1-git-send-email-ldewangan@nvidia.com> <1462361973-27990-3-git-send-email-ldewangan@nvidia.com> <572B173D.6030108@nvidia.com> <572B17DA.901@nvidia.com> <572B3FF9.8080202@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <572B3FF9.8080202-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jon Hunter , thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org, airlied-cv59FeDIM0c@public.gmane.org Cc: gnurou-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On Thursday 05 May 2016 06:13 PM, Jon Hunter wrote: > On 05/05/16 10:52, Laxman Dewangan wrote: >> On Thursday 05 May 2016 03:19 PM, Jon Hunter wrote: >>> On 04/05/16 12:39, Laxman Dewangan wrote: >>>> The function tegra_pmc_readl() returns the u32 type data and hence >>>> change the data type of variable where this data is stored to u32 >>>> type. >>>> >>>> Signed-off-by: Laxman Dewangan >>>> >>>> --- >>>> Changes from V1: >>>> -This is new in series as per discussion on V1 series to use u32 for >>>> tegra_pmc_readl. >>>> >>>> Changes from V2: >>>> - Make unsigned long to u32 for some missed variable from V1. >>>> --- >>>> drivers/soc/tegra/pmc.c | 24 ++++++++++++++---------- >>>> 1 file changed, 14 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c >>>> index 2c3f1f9..eff9425 100644 >>>> --- a/drivers/soc/tegra/pmc.c >>>> +++ b/drivers/soc/tegra/pmc.c >>>> @@ -844,7 +844,8 @@ static void tegra_powergate_init(struct tegra_pmc >>>> *pmc) >>>> static int tegra_io_rail_prepare(unsigned int id, unsigned long >>>> *request, >>>> unsigned long *status, unsigned int *bit) >>>> { >>>> - unsigned long rate, value; >>>> + unsigned long rate; >>>> + u32 value; >>>> *bit = id % 32; >>>> @@ -868,17 +869,18 @@ static int tegra_io_rail_prepare(unsigned int >>>> id, unsigned long *request, >>>> tegra_pmc_writel(DPD_SAMPLE_ENABLE, DPD_SAMPLE); >>>> /* must be at least 200 ns, in APB (PCLK) clock cycles */ >>>> - value = DIV_ROUND_UP(1000000000, rate); >>>> - value = DIV_ROUND_UP(200, value); >>>> + rate = DIV_ROUND_UP(1000000000, rate); >>>> + rate = DIV_ROUND_UP(200, rate); >>>> + value = (u32)rate; >>> Although it is unlikely, I think that we should check it is less >>> than U32_MAX, return an error if it is not. >> rate = DIV_ROUNC_UP(200, rate) means >> >> rate = (200 + rate -1)/rate >> >> and can not be more than 200 in any case (if rate =1). >> So no need of the error check. > OK, yes you are right. In that case there is no need to cast and so I > would leave this code as-is and not change the type. > You mean keep value as unsigned long for value? I think we can still say value as u32 and simply write value = rate Just remove the casting.