ps8640_aux_transfer_msg() programs the AUX address registers, starts the AUX transfer, waits for SWAUX_SEND to clear, and reads the AUX status register. Several of those regmap operations have return values, but the function only checks a stale ret after the status read.
Propagate failures from the address write, transfer start, completion poll, and status read. This avoids returning a transfer length when the bridge register transaction or AUX completion wait failed. Signed-off-by: Pengpeng Hou <[email protected]> --- drivers/gpu/drm/bridge/parade-ps8640.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c index b93514023baa..bf5a36e76c56 100644 --- a/drivers/gpu/drm/bridge/parade-ps8640.c +++ b/drivers/gpu/drm/bridge/parade-ps8640.c @@ -257,8 +257,12 @@ static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux, addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD : ((len - 1) & SWAUX_LENGTH_MASK); - regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len, - ARRAY_SIZE(addr_len)); + ret = regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len, + ARRAY_SIZE(addr_len)); + if (ret) { + DRM_DEV_ERROR(dev, "failed to write AUX address: %d\n", ret); + return ret; + } if (len && (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)) { @@ -274,13 +278,21 @@ static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux, } } - regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND); + ret = regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND); + if (ret) { + DRM_DEV_ERROR(dev, "failed to start AUX transfer: %d\n", ret); + return ret; + } /* Zero delay loop because i2c transactions are slow already */ - regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data, - !(data & SWAUX_SEND), 0, 50 * 1000); + ret = regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data, + !(data & SWAUX_SEND), 0, 50 * 1000); + if (ret) { + DRM_DEV_ERROR(dev, "AUX transfer timed out: %d\n", ret); + return ret; + } - regmap_read(map, PAGE0_SWAUX_STATUS, &data); + ret = regmap_read(map, PAGE0_SWAUX_STATUS, &data); if (ret) { DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n", ret); -- 2.50.1 (Apple Git-155)
