linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lizhi Hou <lizhi.hou@xilinx.com>
To: Tom Rix <trix@redhat.com>, Lizhi Hou <lizhi.hou@xilinx.com>,
	<linux-kernel@vger.kernel.org>
Cc: <linux-fpga@vger.kernel.org>, <maxz@xilinx.com>,
	<sonal.santan@xilinx.com>, <yliu@xilinx.com>,
	<michal.simek@xilinx.com>, <stefanos@xilinx.com>,
	<devicetree@vger.kernel.org>, <mdf@kernel.org>, <robh@kernel.org>,
	Max Zhen <max.zhen@xilinx.com>
Subject: Re: [PATCH V6 XRT Alveo 16/20] fpga: xrt: clock driver
Date: Wed, 19 May 2021 19:49:03 -0700	[thread overview]
Message-ID: <d58eeee5-e47d-4e2b-9b49-15f798c305ed@xilinx.com> (raw)
In-Reply-To: <f4a18fa4-f023-d4e5-0622-e15108de90b9@redhat.com>



On 05/13/2021 08:48 AM, Tom Rix wrote:
>
>
>> +
>> +static int get_freq(struct clock *clock, u16 *freq)
>> +{
>
>> +
>> +     /*
>> +      * Multiply both numerator (mul0) and the denominator (div1) with
>> +      * 1000 to account for fractional portion of divider
>> +      */
>> +
>> +     div1 *= 1000;
>> +     div1 += div_frac1;
>> +     div0 *= div1;
>> +     mul0 *= 1000;
>> +     if (div0 == 0) {
>> +             CLOCK_ERR(clock, "clockwiz 0 divider");
>
> This prevents a divide by zero, but returns 0 without setting freq
>
> A -EINVAL should be returned or freq initialized to some default value
Sure.
>
>> +             return 0;
>> +     }
>> +
>> +     input = mul0 * 100;
>> +     do_div(input, div0);
>> +     *freq = (u16)input;
>> +
>> +     return 0;
>> +}
>> +
>>
>> +
>> +static int clock_verify_freq(struct clock *clock)
>> +{
>> +     u32 lookup_freq, clock_freq_counter, request_in_khz, tolerance;
>> +     int err = 0;
>> +     u16 freq;
>> +
>> +     mutex_lock(&clock->clock_lock);
>> +
>> +     err = get_freq(clock, &freq);
>> +     if (err) {
>> +             xrt_err(clock->xdev, "get freq failed, %d", err);
>> +             goto end;
>> +     }
>> +
>> +     err = get_freq_counter(clock, &clock_freq_counter);
>> +     if (err) {
>> +             xrt_err(clock->xdev, "get freq counter failed, %d", err);
>> +             goto end;
>> +     }
>> +
>> +     lookup_freq = find_matching_freq(freq, frequency_table,
>> + ARRAY_SIZE(frequency_table));
>
> I am running v6 through clang's static analyzer, it shows a problem here
>
> drivers/fpga/xrt/lib/xleaf/clock.c:474:16: warning: 1st function call
> argument is an uninitialized value
>         lookup_freq = find_matching_freq(freq, frequency_table,
>                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> See problem with get_freq above
Sure.

Thanks,
Lizhi
>
> Tom
>
>


  reply	other threads:[~2021-05-20  2:49 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-12  1:53 [PATCH V6 XRT Alveo 00/20] XRT Alveo driver overview Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 01/20] Documentation: fpga: Add a document describing XRT Alveo drivers Lizhi Hou
2021-05-17 14:22   ` Tom Rix
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 02/20] fpga: xrt: driver metadata helper functions Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 03/20] fpga: xrt: xclbin file " Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 04/20] fpga: xrt: xrt-lib driver manager Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 05/20] fpga: xrt: group driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 06/20] fpga: xrt: char dev node helper functions Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 07/20] fpga: xrt: root driver infrastructure Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 08/20] fpga: xrt: " Lizhi Hou
2021-05-13 15:27   ` Tom Rix
2021-05-20  2:48     ` Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 09/20] fpga: xrt: management physical function driver (root) Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 10/20] fpga: xrt: main driver for management function device Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 11/20] fpga: xrt: fpga-mgr and region implementation for xclbin download Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 12/20] fpga: xrt: VSEC driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 13/20] fpga: xrt: User Clock Subsystem driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 14/20] fpga: xrt: ICAP driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 15/20] fpga: xrt: devctl xrt driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 16/20] fpga: xrt: clock driver Lizhi Hou
2021-05-13 15:48   ` Tom Rix
2021-05-20  2:49     ` Lizhi Hou [this message]
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 17/20] fpga: xrt: clock frequency counter driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 18/20] fpga: xrt: DDR calibration driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 19/20] fpga: xrt: partition isolation driver Lizhi Hou
2021-05-12  1:53 ` [PATCH V6 XRT Alveo 20/20] fpga: xrt: Kconfig and Makefile updates for XRT drivers Lizhi Hou

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=d58eeee5-e47d-4e2b-9b49-15f798c305ed@xilinx.com \
    --to=lizhi.hou@xilinx.com \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-fpga@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=max.zhen@xilinx.com \
    --cc=maxz@xilinx.com \
    --cc=mdf@kernel.org \
    --cc=michal.simek@xilinx.com \
    --cc=robh@kernel.org \
    --cc=sonal.santan@xilinx.com \
    --cc=stefanos@xilinx.com \
    --cc=trix@redhat.com \
    --cc=yliu@xilinx.com \
    --subject='Re: [PATCH V6 XRT Alveo 16/20] fpga: xrt: clock driver' \
    /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

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox