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    SubjectRe: [PATCH 1/8] usb: typec: Correct the bit values for the Thunderbolt rounded/non-rounded cable support
    On Mon, Nov 09, 2020 at 04:37:09PM -0800, Utkarsh Patel wrote:
    > Rounded and non-rounded Thunderbolt cables are represented by two bits as
    > per USB Type-C Connector specification v2.0 section F.2.6.
    > Corrected that in the Thunderbolt 3 cable discover mode VDO.
    >
    > Fixes: ca469c292edc ("usb: typec: Add definitions for Thunderbolt 3 Alternate Mode")

    Hold on... Why is this tagged as a fix? What is it fixing?

    Why do we even need this change? The field may have two bits, but
    only one is used: "10b...11b = Reserved".

    > Signed-off-by: Utkarsh Patel <utkarsh.h.patel@intel.com>
    > ---
    > include/linux/usb/typec_tbt.h | 5 +++++
    > 1 file changed, 5 insertions(+)
    >
    > diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
    > index 47c2d501ddce..aad648d14bb3 100644
    > --- a/include/linux/usb/typec_tbt.h
    > +++ b/include/linux/usb/typec_tbt.h
    > @@ -40,11 +40,16 @@ struct typec_thunderbolt_data {
    > #define TBT_CABLE_USB3_PASSIVE 2
    > #define TBT_CABLE_10_AND_20GBPS 3
    > #define TBT_CABLE_ROUNDED BIT(19)
    > +#define TBT_CABLE_ROUNDED_SUPPORT(_vdo_) \
    > + (((_vdo_) & GENMASK(20, 19)) >> 19)
    > +#define TBT_GEN3_NON_ROUNDED 0
    > +#define TBT_GEN3_GEN4_ROUNDED_NON_ROUNDED 1
    > #define TBT_CABLE_OPTICAL BIT(21)
    > #define TBT_CABLE_RETIMER BIT(22)
    > #define TBT_CABLE_LINK_TRAINING BIT(23)
    >
    > #define TBT_SET_CABLE_SPEED(_s_) (((_s_) & GENMASK(2, 0)) << 16)
    > +#define TBT_SET_CABLE_ROUNDED(_g_) (((_g_) & GENMASK(1, 0)) << 19)
    >
    > /* TBT3 Device Enter Mode VDO bits */
    > #define TBT_ENTER_MODE_CABLE_SPEED(s) TBT_SET_CABLE_SPEED(s)

    thanks,

    --
    heikki

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