There's no reason we need to wait here to poll a register over i2c. The i2c bus is inherently slow and delays are practically part of the protocol because we have to wait for the device to respond to any request for a register. Let's rely on the sleeping of the i2c controller instead of adding any sort of delay here in the bridge driver.
Reviewed-by: Douglas Anderson dianders@chromium.org Cc: Laurent Pinchart Laurent.pinchart@ideasonboard.com Cc: Jonas Karlman jonas@kwiboo.se Cc: Jernej Skrabec jernej.skrabec@siol.net Cc: Sean Paul seanpaul@chromium.org Acked-by: Sam Ravnborg sam@ravnborg.org Signed-off-by: Stephen Boyd swboyd@chromium.org --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 87726b9e446f..8276fa50138f 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -881,9 +881,9 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
+ /* Zero delay loop because i2c transactions are slow already */ ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val, - !(val & AUX_CMD_SEND), 200, - 50 * 1000); + !(val & AUX_CMD_SEND), 0, 50 * 1000); if (ret) return ret;