RE: [PATCH v2] scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb

[Avri Altman]

> +Daejun
> 
> Thanks,
> Avri
Bart - How do you want to proceed with this fix?

Thanks,
Avri

> > On 9/9/24 9:45 PM, Avri Altman wrote:
> > > Replace manual offset calculations for response_upiu and prd_table
> > > in
> > > ufshcd_init_lrb() with pre-calculated offsets already stored in the
> > > utp_transfer_req_desc structure. The pre-calculated offsets are set
> > > differently in ufshcd_host_memory_configure() based on the
> > > UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk, ensuring correct alignment and
> > > access.
> > >
> > > Fixes: 26f968d7de82 ("scsi: ufs: Introduce
> > UFSHCD_QUIRK_PRDT_BYTE_GRAN
> > > quirk")
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
> > >
> > > ---
> > > Changes in v2:
> > >   - add Fixes: and Cc: stable tags
> > >   - fix kernel test robot warning about type mismatch by using
> > > le16_to_cpu
> > > ---
> > >   drivers/ufs/core/ufshcd.c | 5 ++---
> > >   1 file changed, 2 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> > > index 8ea5a82503a9..85251c176ef7 100644
> > > --- a/drivers/ufs/core/ufshcd.c
> > > +++ b/drivers/ufs/core/ufshcd.c
> > > @@ -2919,9 +2919,8 @@ static void ufshcd_init_lrb(struct ufs_hba
> > > *hba,
> > struct ufshcd_lrb *lrb, int i)
> > >       struct utp_transfer_req_desc *utrdlp = hba->utrdl_base_addr;
> > >       dma_addr_t cmd_desc_element_addr = hba->ucdl_dma_addr +
> > >               i * ufshcd_get_ucd_size(hba);
> > > -     u16 response_offset = offsetof(struct utp_transfer_cmd_desc,
> > > -                                    response_upiu);
> > > -     u16 prdt_offset = offsetof(struct utp_transfer_cmd_desc, prd_table);
> > > +     u16 response_offset = le16_to_cpu(utrdlp[i].response_upiu_offset);
> > > +     u16 prdt_offset = le16_to_cpu(utrdlp[i].prd_table_offset);
> > >
> > >       lrb->utr_descriptor_ptr = utrdlp + i;
> > >       lrb->utrd_dma_addr = hba->utrdl_dma_addr +
> >
> > Please always Cc the author of the original patch when posting a candidate
> fix.
> >
> > Alim, since the upstream kernel code seems to work fine with Exynos
> > UFS host controllers, is the description of
> > UFSHCD_QUIRK_PRDT_BYTE_GRAN perhaps wrong? I'm referring to the
> following description:
> >
> >         /*
> >          * This quirk needs to be enabled if the host controller regards
> >          * resolution of the values of PRDTO and PRDTL in UTRD as byte.
> >          */
> >         UFSHCD_QUIRK_PRDT_BYTE_GRAN                     = 1 << 9,
> >
> > Thanks,
> >
> > Bart.