Re: [PATCH] platform/x86: wmi: replace usage of found with dedicated list iterator variable

From: Hans de Goede
Date: Mon Apr 11 2022 - 08:41:21 EST


Hi,

On 3/24/22 08:20, Jakob Koschel wrote:
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
>
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable instead of a
> found boolean [1].
>
> This removes the need to use a found variable and simply checking if
> the variable was set, can determine if the break/goto was hit.
>
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@xxxxxxxxxxxxxx/
> Signed-off-by: Jakob Koschel <jakobkoschel@xxxxxxxxx>

Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans


> ---
> drivers/platform/x86/wmi.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
> index 58a23a9adbef..aed293b5af81 100644
> --- a/drivers/platform/x86/wmi.c
> +++ b/drivers/platform/x86/wmi.c
> @@ -1308,21 +1308,20 @@ acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
> static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
> void *context)
> {
> - struct wmi_block *wblock;
> - bool found_it = false;
> + struct wmi_block *wblock = NULL, *iter;
>
> - list_for_each_entry(wblock, &wmi_block_list, list) {
> - struct guid_block *block = &wblock->gblock;
> + list_for_each_entry(iter, &wmi_block_list, list) {
> + struct guid_block *block = &iter->gblock;
>
> - if (wblock->acpi_device->handle == handle &&
> + if (iter->acpi_device->handle == handle &&
> (block->flags & ACPI_WMI_EVENT) &&
> (block->notify_id == event)) {
> - found_it = true;
> + wblock = iter;
> break;
> }
> }
>
> - if (!found_it)
> + if (!wblock)
> return;
>
> /* If a driver is bound, then notify the driver. */
>
> base-commit: f443e374ae131c168a065ea1748feac6b2e76613