[PATCH v2 0/3] Cleanup ahci_broken_lpm()

[PATCH v2 0/3] Cleanup ahci_broken_lpm()

[Niklas Cassel]

Hello all,

This series cleans up ahci_broken_lpm(), and adds ASUSPRO-D840SA to the
table of boards with broken LPM.


Kind regards,
Niklas


Changes since v1:
-Addressed review comments from Hans.


Niklas Cassel (3):
  ata: ahci: Use correct BIOS build date for ThinkPad W541 quirk
  ata: ahci: Refactor ahci_broken_lpm()
  ata: ahci: Disallow LPM for ASUSPRO-D840SA motherboard

 drivers/ata/ahci.c | 41 +++++++++++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 10 deletions(-)

-- 
2.49.0

[PATCH v2 1/3] ata: ahci: Use correct BIOS build date for ThinkPad W541 quirk

[Niklas Cassel]

Fix the TODO in ahci_broken_lpm() by using the proper BIOS build date.

The proper BIOS build date was provided by Hans, see Link.

Link: https://lore.kernel.org/linux-ide/6ea509c8-b38d-4941-8a29-c1117ff3dd5b@redhat.com/
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/ata/ahci.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 163ac909bd06..e7c8357cbc54 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1438,13 +1438,7 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
 				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W541"),
 			},
-			/*
-			 * Note date based on release notes, 2.35 has been
-			 * reported to be good, but I've been unable to get
-			 * a hold of the reporter to get the DMI BIOS date.
-			 * TODO: fix this.
-			 */
-			.driver_data = "20180310", /* 2.35 */
+			.driver_data = "20180409", /* 2.35 */
 		},
 		{ }	/* terminate list */
 	};
-- 
2.49.0

[PATCH v2 2/3] ata: ahci: Refactor ahci_broken_lpm()

[Niklas Cassel]

Currently, the match table in ahci_broken_lpm() contains DMI BIOS dates
of BIOSes that are known to be working.

Having a list of known to be working versions is usually the wrong way to
do things (as this list could theoretically be infinite).

Refactor this match table to contain DMI BIOS dates of BIOSes that are
known to not be working, such that this list can be extended with BIOS
versions (for other boards) that are known to not be working, where there
is no good BIOS version (because all existing versions are broken).

Reviewed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/ata/ahci.c | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index e7c8357cbc54..05ff03b80b85 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1411,34 +1411,50 @@ static bool ahci_broken_suspend(struct pci_dev *pdev)
 static bool ahci_broken_lpm(struct pci_dev *pdev)
 {
 	static const struct dmi_system_id sysids[] = {
-		/* Various Lenovo 50 series have LPM issues with older BIOSen */
+		/* Table contains DMI BIOS dates of BIOSes with broken LPM. */
 		{
 			.matches = {
 				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X250"),
 			},
-			.driver_data = "20180406", /* 1.31 */
+			/*
+			 * 1.31, build date 20180406, has working LPM, mark any
+			 * DMI BIOS date before that as broken.
+			 */
+			.driver_data = "20180405",
 		},
 		{
 			.matches = {
 				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad L450"),
 			},
-			.driver_data = "20180420", /* 1.28 */
+			/*
+			 * 1.28, build date 20180420, has working LPM, mark any
+			 * DMI BIOS date before that as broken.
+			 */
+			.driver_data = "20180419",
 		},
 		{
 			.matches = {
 				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T450s"),
 			},
-			.driver_data = "20180315", /* 1.33 */
+			/*
+			 * 1.33, build date 20180315, has working LPM, mark any
+			 * DMI BIOS date before that as broken.
+			 */
+			.driver_data = "20180314",
 		},
 		{
 			.matches = {
 				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W541"),
 			},
-			.driver_data = "20180409", /* 2.35 */
+			/*
+			 * 2.35, build date 20180409, has working LPM, mark any
+			 * DMI BIOS date before that as broken.
+			 */
+			.driver_data = "20180408",
 		},
 		{ }	/* terminate list */
 	};
@@ -1452,7 +1468,7 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
 	dmi_get_date(DMI_BIOS_DATE, &year, &month, &date);
 	snprintf(buf, sizeof(buf), "%04d%02d%02d", year, month, date);
 
-	return strcmp(buf, dmi->driver_data) < 0;
+	return strcmp(buf, dmi->driver_data) <= 0;
 }
 
 static bool ahci_broken_online(struct pci_dev *pdev)
-- 
2.49.0

[PATCH v2 3/3] ata: ahci: Disallow LPM for ASUSPRO-D840SA motherboard

[Niklas Cassel]

A user has bisected a regression which causes graphical corruptions on his
screen to commit 7627a0edef54 ("ata: ahci: Drop low power policy board
type").

Simply reverting commit 7627a0edef54 ("ata: ahci: Drop low power policy
board type") makes the graphical corruptions on his screen to go away.
(Note: there are no visible messages in dmesg that indicates a problem
with AHCI.)

The user also reports that the problem occurs regardless if there is an
HDD or an SSD connected via AHCI, so the problem is not device related.

The devices also work fine on other motherboards, so it seems specific to
the ASUSPRO-D840SA motherboard.

While enabling low power modes for AHCI is not supposed to affect
completely unrelated hardware, like a graphics card, it does however
allow the system to enter deeper PC-states, which could expose ACPI issues
that were previously not visible (because the system never entered these
lower power states before).

There are previous examples where enabling LPM exposed serious BIOS/ACPI
bugs, see e.g. commit 240630e61870 ("ahci: Disable LPM on Lenovo 50 series
laptops with a too old BIOS").

Since there hasn't been any BIOS update in years for the ASUSPRO-D840SA
motherboard, disable LPM for this board, in order to avoid entering lower
PC-states, which triggers graphical corruptions.

Cc: stable+noautosel@kernel.org # Depends on ahci_broken_lpm() refactor
Reviewed-by: Hans de Goede <hansg@kernel.org>
Reported-by: Andy Yang <andyybtc79@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220111
Fixes: 7627a0edef54 ("ata: ahci: Drop low power policy board type")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/ata/ahci.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 05ff03b80b85..b065440bd911 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1456,6 +1456,17 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
 			 */
 			.driver_data = "20180408",
 		},
+		{
+			.matches = {
+				DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+				DMI_MATCH(DMI_PRODUCT_VERSION, "ASUSPRO D840MB_M840SA"),
+			},
+			/*
+			 * 320, build date 20230208, has broken LPM, no working
+			 * BIOS exists at the time of writing.
+			 */
+			.driver_data = "20230208",
+		},
 		{ }	/* terminate list */
 	};
 	const struct dmi_system_id *dmi = dmi_first_match(sysids);
-- 
2.49.0

Re: [PATCH v2 1/3] ata: ahci: Use correct BIOS build date for ThinkPad W541 quirk

[Hans de Goede]

Hi,

On 10-Jun-25 1:07 PM, Niklas Cassel wrote:
> Fix the TODO in ahci_broken_lpm() by using the proper BIOS build date.
> 
> The proper BIOS build date was provided by Hans, see Link.
> 
> Link: https://lore.kernel.org/linux-ide/6ea509c8-b38d-4941-8a29-c1117ff3dd5b@redhat.com/
> Signed-off-by: Niklas Cassel <cassel@kernel.org>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hansg@kernel.org>

Regards,

Hans



> ---
>  drivers/ata/ahci.c | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> index 163ac909bd06..e7c8357cbc54 100644
> --- a/drivers/ata/ahci.c
> +++ b/drivers/ata/ahci.c
> @@ -1438,13 +1438,7 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
>  				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>  				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W541"),
>  			},
> -			/*
> -			 * Note date based on release notes, 2.35 has been
> -			 * reported to be good, but I've been unable to get
> -			 * a hold of the reporter to get the DMI BIOS date.
> -			 * TODO: fix this.
> -			 */
> -			.driver_data = "20180310", /* 2.35 */
> +			.driver_data = "20180409", /* 2.35 */
>  		},
>  		{ }	/* terminate list */
>  	};

Re: [PATCH v2 1/3] ata: ahci: Use correct BIOS build date for ThinkPad W541 quirk

[Damien Le Moal]

On 6/10/25 8:07 PM, Niklas Cassel wrote:
> Fix the TODO in ahci_broken_lpm() by using the proper BIOS build date.
> 
> The proper BIOS build date was provided by Hans, see Link.
> 
> Link: https://lore.kernel.org/linux-ide/6ea509c8-b38d-4941-8a29-c1117ff3dd5b@redhat.com/
> Signed-off-by: Niklas Cassel <cassel@kernel.org>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v2 2/3] ata: ahci: Refactor ahci_broken_lpm()

[Damien Le Moal]

On 6/10/25 8:08 PM, Niklas Cassel wrote:
> Currently, the match table in ahci_broken_lpm() contains DMI BIOS dates
> of BIOSes that are known to be working.
> 
> Having a list of known to be working versions is usually the wrong way to
> do things (as this list could theoretically be infinite).
> 
> Refactor this match table to contain DMI BIOS dates of BIOSes that are
> known to not be working, such that this list can be extended with BIOS
> versions (for other boards) that are known to not be working, where there
> is no good BIOS version (because all existing versions are broken).
> 
> Reviewed-by: Hans de Goede <hansg@kernel.org>
> Signed-off-by: Niklas Cassel <cassel@kernel.org>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v2 3/3] ata: ahci: Disallow LPM for ASUSPRO-D840SA motherboard

[Damien Le Moal]

On 6/10/25 8:08 PM, Niklas Cassel wrote:
> A user has bisected a regression which causes graphical corruptions on his
> screen to commit 7627a0edef54 ("ata: ahci: Drop low power policy board
> type").
> 
> Simply reverting commit 7627a0edef54 ("ata: ahci: Drop low power policy
> board type") makes the graphical corruptions on his screen to go away.
> (Note: there are no visible messages in dmesg that indicates a problem
> with AHCI.)
> 
> The user also reports that the problem occurs regardless if there is an
> HDD or an SSD connected via AHCI, so the problem is not device related.
> 
> The devices also work fine on other motherboards, so it seems specific to
> the ASUSPRO-D840SA motherboard.
> 
> While enabling low power modes for AHCI is not supposed to affect
> completely unrelated hardware, like a graphics card, it does however
> allow the system to enter deeper PC-states, which could expose ACPI issues
> that were previously not visible (because the system never entered these
> lower power states before).
> 
> There are previous examples where enabling LPM exposed serious BIOS/ACPI
> bugs, see e.g. commit 240630e61870 ("ahci: Disable LPM on Lenovo 50 series
> laptops with a too old BIOS").
> 
> Since there hasn't been any BIOS update in years for the ASUSPRO-D840SA
> motherboard, disable LPM for this board, in order to avoid entering lower
> PC-states, which triggers graphical corruptions.
> 
> Cc: stable+noautosel@kernel.org # Depends on ahci_broken_lpm() refactor
> Reviewed-by: Hans de Goede <hansg@kernel.org>
> Reported-by: Andy Yang <andyybtc79@gmail.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220111
> Fixes: 7627a0edef54 ("ata: ahci: Drop low power policy board type")
> Signed-off-by: Niklas Cassel <cassel@kernel.org>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v2 0/3] Cleanup ahci_broken_lpm()

[Niklas Cassel]

On Tue, 10 Jun 2025 13:07:58 +0200, Niklas Cassel wrote:
> This series cleans up ahci_broken_lpm(), and adds ASUSPRO-D840SA to the
> table of boards with broken LPM.
> 
> 
> Kind regards,
> Niklas
> 
> [...]

Applied to libata/linux.git (for-6.16-fixes), thanks!

[1/3] ata: ahci: Use correct BIOS build date for ThinkPad W541 quirk
      https://git.kernel.org/libata/linux/c/6f29d393
[2/3] ata: ahci: Refactor ahci_broken_lpm()
      https://git.kernel.org/libata/linux/c/e3ea4ae4
[3/3] ata: ahci: Disallow LPM for ASUSPRO-D840SA motherboard
      https://git.kernel.org/libata/linux/c/4b151c71

Kind regards,
Niklas

Re: [PATCH v2 0/3] Cleanup ahci_broken_lpm()

[Niklas Cassel]

On Wed, Jun 11, 2025 at 12:31:17PM +0200, Niklas Cassel wrote:
> On Tue, 10 Jun 2025 13:07:58 +0200, Niklas Cassel wrote:
> > This series cleans up ahci_broken_lpm(), and adds ASUSPRO-D840SA to the
> > table of boards with broken LPM.
> > 
> > 
> > Kind regards,
> > Niklas
> > 
> > [...]
> 
> Applied to libata/linux.git (for-6.16-fixes), thanks!
> 
> [1/3] ata: ahci: Use correct BIOS build date for ThinkPad W541 quirk
>       https://git.kernel.org/libata/linux/c/6f29d393
> [2/3] ata: ahci: Refactor ahci_broken_lpm()
>       https://git.kernel.org/libata/linux/c/e3ea4ae4
> [3/3] ata: ahci: Disallow LPM for ASUSPRO-D840SA motherboard
>       https://git.kernel.org/libata/linux/c/4b151c71

Patch [2/3] and [3/3] have been dropped from for-6.16-fixes, will rework
these as Mikko pointed out that the solution is not really future proof.

Patch [1/3] is kept.


Kind regards,
Niklas