[PATCH 0/2] Add dma-coherent for gs101 UFS dt node

[PATCH 0/2] Add dma-coherent for gs101 UFS dt node

[Peter Griffin]

ufs-exynos driver enables the shareability option for gs101 which
means the descriptors need to be allocated as cacheable.

Fix the DT node and update bindings to add the dma-coherent property.

This fixes the UFS stability issues we have seen with the upstream
UFS driver.

Note this DT fix can go in independently of the other UFS fixes series
I sent recently [1], as the bootloader already leaves the sharability
bits enabled.

regards,

Peter

[1] https://lore.kernel.org/linux-scsi/20250226220414.343659-1-peter.griffin@linaro.org/

To: André Draszik <andre.draszik@linaro.org>
To: Tudor Ambarus <tudor.ambarus@linaro.org>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Alim Akhtar <alim.akhtar@samsung.com>
To: Avri Altman <avri.altman@wdc.com>
To: Bart Van Assche <bvanassche@acm.org>
To: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: kernel-team@android.com
Cc: willmcvicker@google.com

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
---
Peter Griffin (2):
      arm64: dts: exynos: gs101: ufs: add dma-coherent property
      scsi: ufs: dt-bindings: exynos: add dma-coherent property for gs101

 Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml | 2 ++
 arch/arm64/boot/dts/exynos/google/gs101.dtsi                  | 1 +
 2 files changed, 3 insertions(+)
---
base-commit: b323d8e7bc03d27dec646bfdccb7d1a92411f189
change-id: 20250314-ufs-dma-coherent-980f2467690d

Best regards,
-- 
Peter Griffin <peter.griffin@linaro.org>

[PATCH 1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property

[Peter Griffin]

ufs-exynos driver configures the sysreg shareability as
cacheable for gs101 so we need to set the dma-coherent
property so the descriptors are also allocated cacheable.

This fixes the UFS stability issues we have seen with
the upstream UFS driver on gs101.

Fixes: 4c65d7054b4c ("arm64: dts: exynos: gs101: Add ufs and ufs-phy dt nodes")
Cc: stable@vger.kernel.org
Suggested-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
---
 arch/arm64/boot/dts/exynos/google/gs101.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/exynos/google/gs101.dtsi b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
index c5335dd59dfe9fcf8c64d66a466799600f8447b0..cf30128ef004568f01b1c7150c5585ba267d64bc 100644
--- a/arch/arm64/boot/dts/exynos/google/gs101.dtsi
+++ b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
@@ -1360,6 +1360,7 @@ ufs_0: ufs@14700000 {
 				 <&cmu_hsi2 CLK_GOUT_HSI2_SYSREG_HSI2_PCLK>;
 			clock-names = "core_clk", "sclk_unipro_main", "fmp",
 				      "aclk", "pclk", "sysreg";
+			dma-coherent;
 			freq-table-hz = <0 0>, <0 0>, <0 0>, <0 0>, <0 0>, <0 0>;
 			pinctrl-0 = <&ufs_rst_n &ufs_refclk_out>;
 			pinctrl-names = "default";

-- 
2.49.0.rc1.451.g8f38331e32-goog

[PATCH 2/2] scsi: ufs: dt-bindings: exynos: add dma-coherent property for gs101

[Peter Griffin]

dma-coherent property is required for gs101 as ufs-exynos enables
sharability.

Fixes: 438e23b61cd4 ("scsi: ufs: dt-bindings: exynos: Add gs101 compatible")
Cc: stable@vger.kernel.org
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
---
 Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
index 720879820f6616a30cae2db3d4d2d22e847666c4..5dbb7f6a8c354b82685c521e70655e106f702a8d 100644
--- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
+++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
@@ -96,6 +96,8 @@ allOf:
         clock-names:
           minItems: 6
 
+        dma-coherent: true
+
     else:
       properties:
         clocks:

-- 
2.49.0.rc1.451.g8f38331e32-goog

Re: [PATCH 1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property

[André Draszik]

On Fri, 2025-03-14 at 15:38 +0000, Peter Griffin wrote:
> ufs-exynos driver configures the sysreg shareability as
> cacheable for gs101 so we need to set the dma-coherent
> property so the descriptors are also allocated cacheable.
> 
> This fixes the UFS stability issues we have seen with
> the upstream UFS driver on gs101.
> 
> Fixes: 4c65d7054b4c ("arm64: dts: exynos: gs101: Add ufs and ufs-phy dt nodes")
> Cc: stable@vger.kernel.org
> Suggested-by: Will McVicker <willmcvicker@google.com>
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>

Tested-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: André Draszik <andre.draszik@linaro.org>

Re: [PATCH 2/2] scsi: ufs: dt-bindings: exynos: add dma-coherent property for gs101

[André Draszik]

Hi Pete,

On Fri, 2025-03-14 at 15:38 +0000, Peter Griffin wrote:
> dma-coherent property is required for gs101 as ufs-exynos enables
> sharability.
> 
> Fixes: 438e23b61cd4 ("scsi: ufs: dt-bindings: exynos: Add gs101 compatible")
> Cc: stable@vger.kernel.org
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
> ---
>  Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-
> ufs.yaml
> index 720879820f6616a30cae2db3d4d2d22e847666c4..5dbb7f6a8c354b82685c521e70655e106f702a8d 100644
> --- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> +++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> @@ -96,6 +96,8 @@ allOf:
>          clock-names:
>            minItems: 6
>  
> +        dma-coherent: true
> +

This is allowed globally already in this file. Did you meant to make it 'required'?

Cheers,
Andre'

>      else:
>        properties:
>          clocks:
> 

Re: [PATCH 0/2] Add dma-coherent for gs101 UFS dt node

[Bart Van Assche]

On 3/14/25 8:38 AM, Peter Griffin wrote:
> ufs-exynos driver enables the shareability option for gs101 which
> means the descriptors need to be allocated as cacheable.

Shouldn't that code be modified such that the shareability option is
only set if the dma-coherent property is present in the device tree?

Thanks,

Bart.

Re: [PATCH 1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property

[William McVicker]

On 03/14/2025, Peter Griffin wrote:
> ufs-exynos driver configures the sysreg shareability as
> cacheable for gs101 so we need to set the dma-coherent
> property so the descriptors are also allocated cacheable.
> 
> This fixes the UFS stability issues we have seen with
> the upstream UFS driver on gs101.
> 
> Fixes: 4c65d7054b4c ("arm64: dts: exynos: gs101: Add ufs and ufs-phy dt nodes")
> Cc: stable@vger.kernel.org
> Suggested-by: Will McVicker <willmcvicker@google.com>
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>

Tested-by: Will McVicker <willmcvicker@google.com>

Verified I can properly boot to Android recovery with UFS probing and mounting
the partitions in the fstab.

Can you send this to 6.12 stable as well since this is fixing booting issues
with Android?

Thanks,
Will

> ---
>  arch/arm64/boot/dts/exynos/google/gs101.dtsi | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/boot/dts/exynos/google/gs101.dtsi b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> index c5335dd59dfe9fcf8c64d66a466799600f8447b0..cf30128ef004568f01b1c7150c5585ba267d64bc 100644
> --- a/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> +++ b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> @@ -1360,6 +1360,7 @@ ufs_0: ufs@14700000 {
>  				 <&cmu_hsi2 CLK_GOUT_HSI2_SYSREG_HSI2_PCLK>;
>  			clock-names = "core_clk", "sclk_unipro_main", "fmp",
>  				      "aclk", "pclk", "sysreg";
> +			dma-coherent;
>  			freq-table-hz = <0 0>, <0 0>, <0 0>, <0 0>, <0 0>, <0 0>;
>  			pinctrl-0 = <&ufs_rst_n &ufs_refclk_out>;
>  			pinctrl-names = "default";
> 
> -- 
> 2.49.0.rc1.451.g8f38331e32-goog
> 

Re: [PATCH 0/2] Add dma-coherent for gs101 UFS dt node

[William McVicker]

On 03/14/2025, Bart Van Assche wrote:
> On 3/14/25 8:38 AM, Peter Griffin wrote:
> > ufs-exynos driver enables the shareability option for gs101 which
> > means the descriptors need to be allocated as cacheable.
> 
> Shouldn't that code be modified such that the shareability option is
> only set if the dma-coherent property is present in the device tree?

That's what we do downstream and would fix any issues when booting with an
older DT that doesn't have the `dma-coherent` property set. So I agree that
would be a worthy fix (which I did verify fixes the stability issues).

Regards,
Will

> 
> Thanks,
> 
> Bart.

Re: [PATCH 0/2] Add dma-coherent for gs101 UFS dt node

[Peter Griffin]

Hi Bart,

Thanks for the review.

On Fri, 14 Mar 2025 at 16:01, Bart Van Assche <bvanassche@acm.org> wrote:
>
> On 3/14/25 8:38 AM, Peter Griffin wrote:
> > ufs-exynos driver enables the shareability option for gs101 which
> > means the descriptors need to be allocated as cacheable.
>
> Shouldn't that code be modified such that the shareability option is
> only set if the dma-coherent property is present in the device tree?

Yes, I plan to add an extra patch that does what you describe into the
v2 of the UFS fixes series [1] likely later today.

I sent this out separately for Krzysztof's Exynos DT tree in the hope
he will pick it up in the next -rc as this patch fixes how the driver
is configured today, and is also still the configuration we want once
the driver changes land. I should have made that a bit clearer in the
cover letter :)

Thanks,

Peter

[1] https://lore.kernel.org/linux-scsi/20250226220414.343659-1-peter.griffin@linaro.org/

Re: [PATCH 2/2] scsi: ufs: dt-bindings: exynos: add dma-coherent property for gs101

[Krzysztof Kozlowski]

On Fri, Mar 14, 2025 at 03:38:03PM +0000, Peter Griffin wrote:
> dma-coherent property is required for gs101 as ufs-exynos enables
> sharability.
> 
> Fixes: 438e23b61cd4 ("scsi: ufs: dt-bindings: exynos: Add gs101 compatible")
> Cc: stable@vger.kernel.org

This change is a noop and fixes nothing, which you can test by testing
your DTS without and with this patch.

Best regards,
Krzysztof

Re: [PATCH 2/2] scsi: ufs: dt-bindings: exynos: add dma-coherent property for gs101

[Peter Griffin]

Hi André

On Fri, 14 Mar 2025 at 15:59, André Draszik <andre.draszik@linaro.org> wrote:
>
> Hi Pete,
>
> On Fri, 2025-03-14 at 15:38 +0000, Peter Griffin wrote:
> > dma-coherent property is required for gs101 as ufs-exynos enables
> > sharability.
> >
> > Fixes: 438e23b61cd4 ("scsi: ufs: dt-bindings: exynos: Add gs101 compatible")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
> > ---
> >  Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-
> > ufs.yaml
> > index 720879820f6616a30cae2db3d4d2d22e847666c4..5dbb7f6a8c354b82685c521e70655e106f702a8d 100644
> > --- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> > +++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml
> > @@ -96,6 +96,8 @@ allOf:
> >          clock-names:
> >            minItems: 6
> >
> > +        dma-coherent: true
> > +
>
> This is allowed globally already in this file. Did you meant to make it 'required'?

I hadn't noticed it was already handled further up in the yaml. In
which case this patch can be dropped entirely.

Thanks,

Peter

Re: [PATCH 1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property

[Peter Griffin]

Hi Krzysztof,

On Fri, 14 Mar 2025 at 15:38, Peter Griffin <peter.griffin@linaro.org> wrote:
>
> ufs-exynos driver configures the sysreg shareability as
> cacheable for gs101 so we need to set the dma-coherent
> property so the descriptors are also allocated cacheable.
>
> This fixes the UFS stability issues we have seen with
> the upstream UFS driver on gs101.
>
> Fixes: 4c65d7054b4c ("arm64: dts: exynos: gs101: Add ufs and ufs-phy dt nodes")
> Cc: stable@vger.kernel.org
> Suggested-by: Will McVicker <willmcvicker@google.com>
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
> ---

Friendly ping about this patch :)

Peter

Re: [PATCH 1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property

[Krzysztof Kozlowski]

On 27/06/2025 18:28, Peter Griffin wrote:
> Hi Krzysztof,
> 
> On Fri, 14 Mar 2025 at 15:38, Peter Griffin <peter.griffin@linaro.org> wrote:
>>
>> ufs-exynos driver configures the sysreg shareability as
>> cacheable for gs101 so we need to set the dma-coherent
>> property so the descriptors are also allocated cacheable.
>>
>> This fixes the UFS stability issues we have seen with
>> the upstream UFS driver on gs101.
>>
>> Fixes: 4c65d7054b4c ("arm64: dts: exynos: gs101: Add ufs and ufs-phy dt nodes")
>> Cc: stable@vger.kernel.org
>> Suggested-by: Will McVicker <willmcvicker@google.com>
>> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
>> ---
> 
> Friendly ping about this patch :)

Thanks, I dropped it from my queue based on comments on the bindings
patch, but that was too hasty.

I applied it now.

Best regards,
Krzysztof

Re: (subset) [PATCH 1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property

[Krzysztof Kozlowski]

On Fri, 14 Mar 2025 15:38:02 +0000, Peter Griffin wrote:
> ufs-exynos driver configures the sysreg shareability as
> cacheable for gs101 so we need to set the dma-coherent
> property so the descriptors are also allocated cacheable.
> 
> This fixes the UFS stability issues we have seen with
> the upstream UFS driver on gs101.
> 
> [...]

Applied, thanks!

[1/2] arm64: dts: exynos: gs101: ufs: add dma-coherent property
      https://git.kernel.org/krzk/linux/c/4292564c71cffd8094abcc52dd4840870d05cd30

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>