[bug report] drm/msm: dsi: Handle dual-channel for 6G as well

[Jessica Zhang]

Hey Dmitry,

On 10/15/2021 11:24 AM, Dmitry Baryshkov wrote:
> On Fri, 15 Oct 2021 at 04:43, Jessica Zhang <jesszhan at codeaurora.org> wrote:
>> Hey Dan,
>>
>> On 10/1/2021 5:31 AM, Dan Carpenter wrote:
>>> Hello Sean Paul,
>>>
>>> The patch a6bcddbc2ee1: "drm/msm: dsi: Handle dual-channel for 6G as
>>> well" from Jul 25, 2018, leads to the following
>>> Smatch static checker warning:
>>>
>>>        drivers/gpu/drm/msm/dsi/dsi_host.c:729 dsi_calc_clk_rate_6g()
>>>        warn: wrong type for 'msm_host->esc_clk_rate' (should be 'ulong')
>>>
>>> drivers/gpu/drm/msm/dsi/dsi_host.c
>>>       721 int dsi_calc_clk_rate_6g(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>>>       722 {
>>>       723         if (!msm_host->mode) {
>>>       724                 pr_err("%s: mode not set\n", __func__);
>>>       725                 return -EINVAL;
>>>       726         }
>>>       727
>>>       728         dsi_calc_pclk(msm_host, is_bonded_dsi);
>>> --> 729         msm_host->esc_clk_rate = clk_get_rate(msm_host->esc_clk);
>>>                   ^^^^^^^^^^^^^^^^^^^^^^
>>> I don't know why Smatch is suddenly warning about ancient msm code, but
>>> clock rates should be unsigned long.  (I don't remember why).
>>>
>>>       730         return 0;
>>>       731 }
>> I'm unable to recreate the warning with Smatch. After running
>> build_kernel_data.sh, I ran `<path to smatch>/smatch_scripts/kchecker
>> drivers/gpu/drm/msm/dsi/dsi_host.c` and got the following output:
>>
>> CHECK scripts/mod/empty.c
>> CALL scripts/checksyscalls.sh
>> CALL scripts/atomic/check-atomics.sh
>> CHECK arch/arm64/kernel/vdso/vgettimeofday.c
>> CC drivers/gpu/drm/msm/dsi/dsi_host.o
>> CHECK drivers/gpu/drm/msm/dsi/dsi_host.c
>> drivers/gpu/drm/msm/dsi/dsi_host.c:2380 msm_dsi_host_power_on() warn:
>> missing error code 'ret'
>>
>> Is there a specific .config you're using (that's not the default
>> mainline defconfig)? If so, can you please share it?
> Are you running your checks with ARM32 or ARM64 in mind?
> Note, esc_clk_rate is u32, while clk_get_rate()'s returns unsigned long.
> It would make sense to change all three clocks rates in msm_dsi_host
> struct (and several places where they are used) to unsigned long.

Thanks for the response. I'm aware of what's causing this issue and how 
to fix it, but I want to also be able to recreate the warning locally 
with Smatch.

Thanks,

Jessica Zhang

>> Thanks,
>>
>> Jessica Zhang
>>
>>> regards,
>>> dan carpenter
>
>