Linux SPI subsystem development
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jay Fang <f.fangjian@huawei.com>
Cc: linux-spi@vger.kernel.org, broonie@kernel.org, huangdaode@huawei.com
Subject: Re: [PATCH] spi: cadence-quadspi: Silence shiftTooManyBitsSigned warning
Date: Thu, 4 Mar 2021 16:08:45 +0300	[thread overview]
Message-ID: <20210304130845.GE2222@kadam> (raw)
In-Reply-To: <1614854872-8694-1-git-send-email-f.fangjian@huawei.com>

On Thu, Mar 04, 2021 at 06:47:52PM +0800, Jay Fang wrote:
> drivers/spi/spi-cadence-quadspi.c:267:18: warning: Shifting signed 32-bit
> value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
>     return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
>                     ^
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Jay Fang <f.fangjian@huawei.com>
> ---
>  drivers/spi/spi-cadence-quadspi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
> index 442cc7c..9a2798a5 100644
> --- a/drivers/spi/spi-cadence-quadspi.c
> +++ b/drivers/spi/spi-cadence-quadspi.c
> @@ -264,7 +264,7 @@ static bool cqspi_is_idle(struct cqspi_st *cqspi)
>  {
>  	u32 reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
>  
> -	return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
> +	return reg & (1UL << CQSPI_REG_CONFIG_IDLE_LSB);

This is always going to be false because reg is a u32.

regards,
dan carpenter


  reply	other threads:[~2021-03-04 13:15 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-04 10:47 [PATCH] spi: cadence-quadspi: Silence shiftTooManyBitsSigned warning Jay Fang
2021-03-04 13:08 ` Dan Carpenter [this message]
2021-03-04 19:34   ` Pratyush Yadav
2021-03-05  9:42     ` Dan Carpenter
2021-03-08 16:08 ` Mark Brown

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210304130845.GE2222@kadam \
    --to=dan.carpenter@oracle.com \
    --cc=broonie@kernel.org \
    --cc=f.fangjian@huawei.com \
    --cc=huangdaode@huawei.com \
    --cc=linux-spi@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox