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

[Jessica Zhang]

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?

Thanks,

Jessica Zhang

> regards,
> dan carpenter