Re: [PATCH v2] soc: qcom: ubwc: disable bank swizzling for Glymur platform

[Bjorn Andersson]

On Fri, Mar 06, 2026 at 05:15:32PM +0200, Dmitry Baryshkov wrote:
> On Sat, Feb 28, 2026 at 08:34:27PM +0200, Dmitry Baryshkov wrote:
> > Due to the way the DDR controller is organized on Glymur, hardware
> > engineers strongly recommended disabling UBWC bank swizzling on Glymur.
> > Follow that recommendation.
> > 
> > Fixes: 9b21c3bd2480 ("soc: qcom: ubwc: Add configuration Glymur platform")
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> > ---
> > Changes in v2:
> > - Fix the syntax error...
> > - Link to v1: https://lore.kernel.org/r/20260228-fix-glymur-ubwc-v1-1-d80e3fe0dcc7@xxxxxxxxxxxxxxxx
> > ---
> >  drivers/soc/qcom/ubwc_config.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/drivers/soc/qcom/ubwc_config.c b/drivers/soc/qcom/ubwc_config.c
> > index 1c25aaf55e52..8304463f238a 100644
> > --- a/drivers/soc/qcom/ubwc_config.c
> > +++ b/drivers/soc/qcom/ubwc_config.c
> > @@ -231,8 +231,7 @@ static const struct qcom_ubwc_cfg_data x1e80100_data = {
> >  static const struct qcom_ubwc_cfg_data glymur_data = {
> >  	.ubwc_enc_version = UBWC_5_0,
> >  	.ubwc_dec_version = UBWC_5_0,
> > -	.ubwc_swizzle = UBWC_SWIZZLE_ENABLE_LVL2 |
> > -			UBWC_SWIZZLE_ENABLE_LVL3,
> > +	.ubwc_swizzle = 0,
> >  	.ubwc_bank_spread = true,
> >  	/* TODO: highest_bank_bit = 15 for LP_DDR4 */
> >  	.highest_bank_bit = 16,
> 
> Carrying over from v1 discussion.
> 
> Reviewed-by: Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>
> 
> It depends on the fix which is currently a part of msm-fixes for the
> device to function correctly. Raised the question on IRC regarding the
> immutable tag or any other proper way to merge it.
> 

Sorry, I did see your question on IRC, but didn't follow up and forgot
to ask about it.

What do you mean with "depends on"? Why do we need an immutable tag?

Regards,
Bjorn

> > 
> > ---
> > base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
> > change-id: 20260228-fix-glymur-ubwc-f673d5ca0581
> > 
> > Best regards,
> > -- 
> > With best wishes
> > Dmitry
> > 
> 
> -- 
> With best wishes
> Dmitry