diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/bridge/dw_hdmi_qp.h | 1 | ||||
| -rw-r--r-- | include/drm/display/drm_dp_helper.h | 57 |
2 files changed, 38 insertions, 20 deletions
diff --git a/include/drm/bridge/dw_hdmi_qp.h b/include/drm/bridge/dw_hdmi_qp.h index 3f461f6b9bbf..3af12f82da2c 100644 --- a/include/drm/bridge/dw_hdmi_qp.h +++ b/include/drm/bridge/dw_hdmi_qp.h @@ -34,5 +34,6 @@ struct dw_hdmi_qp_plat_data { struct dw_hdmi_qp *dw_hdmi_qp_bind(struct platform_device *pdev, struct drm_encoder *encoder, const struct dw_hdmi_qp_plat_data *plat_data); +void dw_hdmi_qp_suspend(struct device *dev, struct dw_hdmi_qp *hdmi); void dw_hdmi_qp_resume(struct device *dev, struct dw_hdmi_qp *hdmi); #endif /* __DW_HDMI_QP__ */ diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index df2f24b950e4..14d2859f0bda 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -552,6 +552,22 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, void *buffer, size_t size); /** + * drm_dp_dpcd_readb() - read a single byte from the DPCD + * @aux: DisplayPort AUX channel + * @offset: address of the register to read + * @valuep: location where the value of the register will be stored + * + * Returns the number of bytes transferred (1) on success, or a negative + * error code on failure. In most of the cases you should be using + * drm_dp_dpcd_read_byte() instead. + */ +static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux, + unsigned int offset, u8 *valuep) +{ + return drm_dp_dpcd_read(aux, offset, valuep, 1); +} + +/** * drm_dp_dpcd_read_data() - read a series of bytes from the DPCD * @aux: DisplayPort AUX channel (SST or MST) * @offset: address of the (first) register to read @@ -570,12 +586,29 @@ static inline int drm_dp_dpcd_read_data(struct drm_dp_aux *aux, void *buffer, size_t size) { int ret; + size_t i; + u8 *buf = buffer; ret = drm_dp_dpcd_read(aux, offset, buffer, size); - if (ret < 0) - return ret; - if (ret < size) - return -EPROTO; + if (ret >= 0) { + if (ret < size) + return -EPROTO; + return 0; + } + + /* + * Workaround for USB-C hubs/adapters with buggy firmware that fail + * multi-byte AUX reads but work with single-byte reads. + * Known affected devices: + * - Lenovo USB-C to VGA adapter (VIA VL817, idVendor=17ef, idProduct=7217) + * - Dell DA310 USB-C hub (idVendor=413c, idProduct=c010) + * Attempt byte-by-byte reading as a fallback. + */ + for (i = 0; i < size; i++) { + ret = drm_dp_dpcd_readb(aux, offset + i, &buf[i]); + if (ret < 0) + return ret; + } return 0; } @@ -610,22 +643,6 @@ static inline int drm_dp_dpcd_write_data(struct drm_dp_aux *aux, } /** - * drm_dp_dpcd_readb() - read a single byte from the DPCD - * @aux: DisplayPort AUX channel - * @offset: address of the register to read - * @valuep: location where the value of the register will be stored - * - * Returns the number of bytes transferred (1) on success, or a negative - * error code on failure. In most of the cases you should be using - * drm_dp_dpcd_read_byte() instead. - */ -static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux, - unsigned int offset, u8 *valuep) -{ - return drm_dp_dpcd_read(aux, offset, valuep, 1); -} - -/** * drm_dp_dpcd_writeb() - write a single byte to the DPCD * @aux: DisplayPort AUX channel * @offset: address of the register to write |