Re: [PATCH v2 3/5] platform/x86/amd/pmc: Add delay_suspend module parameter

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Sat, 9 May 2026, Daniel Gibson wrote:

> Enabling the new delay_suspend module parameter delays suspend for
> 2.5 seconds which is known to help for some AMD-based Lenovo Laptops
> that otherwise failed to send/receive events for key presses or the
> lid switch after s2idle.
> Apparently the EC needs to do some things in the background before

Please fill in paragraphs to ~72 chars or clearly make another 
paragraph with a line in between, if that's what you want.

> suspend or it gets into a bad state.
> 
> There are many reports of AMD-based laptops (mostly but not exclusively
> IdeaPads) about similar issues on the web; this parameter gives
> affected users an easy way to try out if their issues have the same
> root cause and to work around them until their specific device is added
> to the quirks list.
> I added a note to the parameter description encouraging users to report
> their device so it can be added to the quirks list, inspired by a
> similar request in parameter descriptions of the ideapad-laptop module.
> 
> The module parameter can be set to "1" to explicitly enable it,
> "0" to disable it even on devices that are assumed to be affected,
> or -1 (the default) to enable it if the device is assumed to be affected
> (according to fwbug_list[])
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=221383
> Signed-off-by: Daniel Gibson <daniel@gibson.sh>
> ---
>  drivers/platform/x86/amd/pmc/pmc.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c
> index 6bafd8661d68..2d3d180c15d2 100644
> --- a/drivers/platform/x86/amd/pmc/pmc.c
> +++ b/drivers/platform/x86/amd/pmc/pmc.c
> @@ -16,6 +16,7 @@
>  #include <linux/bits.h>
>  #include <linux/debugfs.h>
>  #include <linux/delay.h>
> +#include <linux/dmi.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
>  #include <linux/limits.h>
> @@ -89,6 +90,11 @@ static bool disable_workarounds;
>  module_param(disable_workarounds, bool, 0644);
>  MODULE_PARM_DESC(disable_workarounds, "Disable workarounds for platform bugs");
>  
> +static int delay_suspend = -1;
> +module_param(delay_suspend, int, 0644);
> +MODULE_PARM_DESC(delay_suspend,
> +		 "Delays s2idle by 2.5 seconds to work around buggy ECs, often causing keyboard issues after suspend. 0: don't delay, 1: do delay, -1 (default): let amd_pmc decide. If you need this please report this to: platform-driver-x86@vger.kernel.org");
> +
>  static struct amd_pmc_dev pmc;
>  
>  static inline u32 amd_pmc_reg_read(struct amd_pmc_dev *dev, int reg_offset)
> @@ -625,8 +631,23 @@ static bool amd_pmc_want_suspend_delay(struct amd_pmc_dev *pdev)
>  	 *
>  	 * See https://bugzilla.kernel.org/show_bug.cgi?id=221383
>  	 */
> -	if (!disable_workarounds && amd_pmc_quirk_need_suspend_delay(pdev)) {
> -		dev_info(pdev->dev, "Delaying suspend by 2.5s to avoid platform bug\n");
> +	if (amd_pmc_quirk_need_suspend_delay(pdev)) {
> +		/*
> +		 * delay_suspend=1 force-enables this, otherwise it can be
> +		 * disabled with disable_workarounds or delay_suspend=0
> +		 */
> +		if (delay_suspend == 1 || (delay_suspend == -1 && !disable_workarounds)) {
> +			dev_info(pdev->dev, "Delaying suspend by 2.5s to avoid platform bug\n");
> +			return true;
> +		}
> +		dev_info(pdev->dev, "Not delaying suspend because of module parameter, even though your device is assumed to need it!\n");
> +	} else if (delay_suspend == 1) {

At least the parameter interactions madness is a bit more contained now 
that it's in these smaller functions. :-/

Still not a big fan of it but I guess it's not worth fighting over 
something that normally shouldn't be needed (if we've all the needed 
quirk info in place).

> +		dev_info(pdev->dev, "Delaying suspend by 2.5s because delay_suspend=1. If this solves problems on your machine, please report this whole line to: platform-driver-x86@vger.kernel.org so it can be automatically detected as affected in the future. System Vendor: \"%s\" Product Name: \"%s\" Product Family: \"%s\" Board Vendor: \"%s\" Board Name: \"%s\"\n",
> +			 dmi_get_system_info(DMI_SYS_VENDOR),
> +			 dmi_get_system_info(DMI_PRODUCT_NAME),
> +			 dmi_get_system_info(DMI_PRODUCT_FAMILY),
> +			 dmi_get_system_info(DMI_BOARD_VENDOR),
> +			 dmi_get_system_info(DMI_BOARD_NAME));
>  		return true;
>  	}
>  	return false;
> 

-- 
 i.