scsi: ufs: pltfrm: Add quirk for R-Car S4 lacking lanes-per-direction

Since commit e72323f3b09f ("scsi: ufs: core: Configure only active lanes
during link"), the following error is observed on R-Car S4:

    ufshcd-renesas e6860000.ufs: Tx lane mismatch [config,reported] [2,1]
    ufshcd-renesas e6860000.ufs: link startup failed -67
    ufshcd-renesas e6860000.ufs: error -ENOLINK: Initialization failed with error -67
    ufshcd-renesas e6860000.ufs: probe with driver ufshcd-renesas failed with error -67

R-Car S4 has one UFS lane per direction, as described in section 152.1 of
its hardware manual.  Without lanes-per-direction, the UFS platform driver
defaults to two lanes.

Previously, the core used PA_CONNECTEDRXDATALANES and
PA_CONNECTEDTXDATALANES to configure the link without checking them against
lanes-per-direction, so the missing property did not prevent
initialization.

While fixing the R-Car S4 DTS is the proper solution, doing only that would
still break backwards compatibility with existing DTBs.  Hence add a quirk
to let lanes-per-direction default to one on R-Car S4.

Fixes: e72323f3b09f9c89 ("scsi: ufs: core: Configure only active lanes during link")
Reported-by: Koichiro Den <den@valinux.co.jp>
Closes: https://lore.kernel.org/20260911073058.253000-1-den@valinux.co.jp
Cc: stable@vger.kernel.org # 7.2+
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/ae0cc2bd764e6dfffce99db3d8b44a55887c508c.1789394185.git.geert+renesas@glider.be
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>

0 files changed, 0 insertions, 0 deletions