| Message ID | 20190605070507.11417-9-andrew.smirnov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tc358767 driver improvements | expand |
On 05.06.2019 09:05, Andrey Smirnov wrote: > According to the datasheet tc358767 can transfer up to 16 bytes via > its AUX channel, so the artificial limit of 8 apperas to be too > low. However only up to 15-bytes seem to be actually supported and > trying to use 16-byte transfers results in transfers failing > sporadically (with bogus status in case of I2C transfers), so limit it > to 15. > > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> > Cc: Archit Taneja <architt@codeaurora.org> Please remove Archit's mail (from all patches), it is no longer valid. Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> -- Regards Andrzej > Cc: Andrzej Hajda <a.hajda@samsung.com> > Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com> > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> > Cc: Andrey Gusakov <andrey.gusakov@cogentembedded.com> > Cc: Philipp Zabel <p.zabel@pengutronix.de> > Cc: Cory Tusar <cory.tusar@zii.aero> > Cc: Chris Healy <cphealy@gmail.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: dri-devel@lists.freedesktop.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/gpu/drm/bridge/tc358767.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c > index 260fbcd0271e..0125e2f7e076 100644 > --- a/drivers/gpu/drm/bridge/tc358767.c > +++ b/drivers/gpu/drm/bridge/tc358767.c > @@ -374,7 +374,7 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux, > struct drm_dp_aux_msg *msg) > { > struct tc_data *tc = aux_to_tc(aux); > - size_t size = min_t(size_t, 8, msg->size); > + size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size); > u8 request = msg->request & ~DP_AUX_I2C_MOT; > int ret; >
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 260fbcd0271e..0125e2f7e076 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -374,7 +374,7 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { struct tc_data *tc = aux_to_tc(aux); - size_t size = min_t(size_t, 8, msg->size); + size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size); u8 request = msg->request & ~DP_AUX_I2C_MOT; int ret;
According to the datasheet tc358767 can transfer up to 16 bytes via its AUX channel, so the artificial limit of 8 apperas to be too low. However only up to 15-bytes seem to be actually supported and trying to use 16-byte transfers results in transfers failing sporadically (with bogus status in case of I2C transfers), so limit it to 15. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Archit Taneja <architt@codeaurora.org> Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Andrey Gusakov <andrey.gusakov@cogentembedded.com> Cc: Philipp Zabel <p.zabel@pengutronix.de> Cc: Cory Tusar <cory.tusar@zii.aero> Cc: Chris Healy <cphealy@gmail.com> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org --- drivers/gpu/drm/bridge/tc358767.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)