| Message ID | 20230329215159.2046932-1-rdbabiera@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v1] usb: typec: altmodes/displayport: Fix configure initial pin assignment | expand |
On Wed, Mar 29, 2023 at 09:51:59PM +0000, RD Babiera wrote: > While determining the initial pin assignment to be sent in the configure > message, using the DP_PIN_ASSIGN_DP_ONLY_MASK mask causes the DFP_U to > send both Pin Assignment C and E when both are supported by the DFP_U and > UFP_U. The spec (Table 5-7 DFP_U Pin Assignment Selection Mandates, > VESA DisplayPort Alt Mode Standard v2.0) indicates that the DFP_U never > selects Pin Assignment E when Pin Assignment C is offered. > > Update the DP_PIN_ASSIGN_DP_ONLY_MASK conditional to intially select only > Pin Assignment C if it is available. > > Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") > Cc: stable@vger.kernel.org > Signed-off-by: RD Babiera <rdbabiera@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > drivers/usb/typec/altmodes/displayport.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c > index 662cd043b50e..8f3e884222ad 100644 > --- a/drivers/usb/typec/altmodes/displayport.c > +++ b/drivers/usb/typec/altmodes/displayport.c > @@ -112,8 +112,12 @@ static int dp_altmode_configure(struct dp_altmode *dp, u8 con) > if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC && > pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK) > pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK; > - else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) > + else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) { > pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK; > + /* Default to pin assign C if available */ > + if (pin_assign & BIT(DP_PIN_ASSIGN_C)) > + pin_assign = BIT(DP_PIN_ASSIGN_C); > + } > > if (!pin_assign) > return -EINVAL; > > base-commit: 97318d6427f62b723c89f4150f8f48126ef74961 > -- > 2.40.0.348.gf938b09366-goog
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c index 662cd043b50e..8f3e884222ad 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -112,8 +112,12 @@ static int dp_altmode_configure(struct dp_altmode *dp, u8 con) if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC && pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK) pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK; - else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) + else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) { pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK; + /* Default to pin assign C if available */ + if (pin_assign & BIT(DP_PIN_ASSIGN_C)) + pin_assign = BIT(DP_PIN_ASSIGN_C); + } if (!pin_assign) return -EINVAL;
While determining the initial pin assignment to be sent in the configure message, using the DP_PIN_ASSIGN_DP_ONLY_MASK mask causes the DFP_U to send both Pin Assignment C and E when both are supported by the DFP_U and UFP_U. The spec (Table 5-7 DFP_U Pin Assignment Selection Mandates, VESA DisplayPort Alt Mode Standard v2.0) indicates that the DFP_U never selects Pin Assignment E when Pin Assignment C is offered. Update the DP_PIN_ASSIGN_DP_ONLY_MASK conditional to intially select only Pin Assignment C if it is available. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera <rdbabiera@google.com> --- drivers/usb/typec/altmodes/displayport.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) base-commit: 97318d6427f62b723c89f4150f8f48126ef74961