On Thu, Dec 20, 2018 at 05:35:24PM +0530, Buland Singh wrote:
> Commit '3d035f580699 ("drivers/char/hpet.c: allow user controlled mmap for
> user processes")' introduced a new kernel command line parameter hpet_mmap,
> that is required to expose the memory map of the HPET registers to
> user-space. Unfortunately the kernel command line parameter 'hpet_mmap' is
> broken and never takes effect due to missing '=' character in the __setup()
> code of hpet_mmap_enable.
>
> Before this patch:
>
> dmesg output with the kernel command line parameter hpet_mmap=1
>
> [ 0.204152] HPET mmap disabled
>
> dmesg output with the kernel command line parameter hpet_mmap=0
>
> [ 0.204192] HPET mmap disabled
>
> After this patch:
>
> dmesg output with the kernel command line parameter hpet_mmap=1
>
> [ 0.203945] HPET mmap enabled
>
> dmesg output with the kernel command line parameter hpet_mmap=0
>
> [ 0.204652] HPET mmap disabled
>
> Fixes: 3d035f580699 ("drivers/char/hpet.c: allow user controlled mmap for user processes")
> Signed-off-by: Buland Singh <bsingh@xxxxxxxxxx>
> ---
> drivers/char/hpet.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
> index 4a22b4b41aef..9bffcd37cc7b 100644
> --- a/drivers/char/hpet.c
> +++ b/drivers/char/hpet.c
> @@ -377,7 +377,7 @@ static __init int hpet_mmap_enable(char *str)
> pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled");
> return 1;
> }
> -__setup("hpet_mmap", hpet_mmap_enable);
> +__setup("hpet_mmap=", hpet_mmap_enable);
This has _never_ worked? Since 3.13? Why not just remove the thing as
it is obvious no one actually has ever used it. That would make the
code even simpler :)
thanks,
greg k-h
