diff options
| author | Pablo Sun <pablo.sun@mediatek.com> | 2022-08-04 06:48:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-18 22:20:07 +0300 |
| commit | c1e5c2f0cb8a22ec2e14af92afc7006491bebabb (patch) | |
| tree | e194d9d0a768e8bf840fc17ee0aeb31e2e33d26f | |
| parent | 1bcafc0498038a5a2ce5a9b888c39f1c32242cec (diff) | |
| download | linux-c1e5c2f0cb8a22ec2e14af92afc7006491bebabb.tar.xz | |
usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles
Fix incorrect pin assignment values when connecting to a monitor with
Type-C receptacle instead of a plug.
According to specification, an UFP_D receptacle's pin assignment
should came from the UFP_D pin assignments field (bit 23:16), while
an UFP_D plug's assignments are described in the DFP_D pin assignments
(bit 15:8) during Mode Discovery.
For example the LG 27 UL850-W is a monitor with Type-C receptacle.
The monitor responds to MODE DISCOVERY command with following
DisplayPort Capability flag:
dp->alt->vdo=0x140045
The existing logic only take cares of UPF_D plug case,
and would take the bit 15:8 for this 0x140045 case.
This results in an non-existing pin assignment 0x0 in
dp_altmode_configure.
To fix this problem a new set of macros are introduced
to take plug/receptacle differences into consideration.
Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@vger.kernel.org
Co-developed-by: Pablo Sun <pablo.sun@mediatek.com>
Co-developed-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: Guillaume Ranquet <granquet@baylibre.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Pablo Sun <pablo.sun@mediatek.com>
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Link: https://lore.kernel.org/r/20220804034803.19486-1-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/typec/altmodes/displayport.c | 4 | ||||
| -rw-r--r-- | include/linux/usb/typec_dp.h | 5 |
2 files changed, 7 insertions, 2 deletions
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c index c1d8c23baa39..de66a2949e33 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -99,8 +99,8 @@ static int dp_altmode_configure(struct dp_altmode *dp, u8 con) case DP_STATUS_CON_UFP_D: case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */ conf |= DP_CONF_UFP_U_AS_UFP_D; - pin_assign = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo) & - DP_CAP_UFP_D_PIN_ASSIGN(dp->port->vdo); + pin_assign = DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo) & + DP_CAP_PIN_ASSIGN_DFP_D(dp->port->vdo); break; default: break; diff --git a/include/linux/usb/typec_dp.h b/include/linux/usb/typec_dp.h index cfb916cccd31..8d09c2f0a9b8 100644 --- a/include/linux/usb/typec_dp.h +++ b/include/linux/usb/typec_dp.h @@ -73,6 +73,11 @@ enum { #define DP_CAP_USB BIT(7) #define DP_CAP_DFP_D_PIN_ASSIGN(_cap_) (((_cap_) & GENMASK(15, 8)) >> 8) #define DP_CAP_UFP_D_PIN_ASSIGN(_cap_) (((_cap_) & GENMASK(23, 16)) >> 16) +/* Get pin assignment taking plug & receptacle into consideration */ +#define DP_CAP_PIN_ASSIGN_UFP_D(_cap_) ((_cap_ & DP_CAP_RECEPTACLE) ? \ + DP_CAP_UFP_D_PIN_ASSIGN(_cap_) : DP_CAP_DFP_D_PIN_ASSIGN(_cap_)) +#define DP_CAP_PIN_ASSIGN_DFP_D(_cap_) ((_cap_ & DP_CAP_RECEPTACLE) ? \ + DP_CAP_DFP_D_PIN_ASSIGN(_cap_) : DP_CAP_UFP_D_PIN_ASSIGN(_cap_)) /* DisplayPort Status Update VDO bits */ #define DP_STATUS_CONNECTION(_status_) ((_status_) & 3) |