On Tue, Jan 31, 2017 at 11:45:48AM +0000, John Keeping wrote: > On Mon, 30 Jan 2017 15:09:55 -0500, Sean Paul wrote: > > > On Mon, Jan 30, 2017 at 06:16:36PM +0000, John Keeping wrote: > > > On Mon, 30 Jan 2017 13:01:46 -0500, Sean Paul wrote: > > > > > > > On Sun, Jan 29, 2017 at 01:24:26PM +0000, John Keeping wrote: > > > > > As a side-effect of this, encode the endianness explicitly rather than > > > > > casting a u16. > > > > > > > > > > Signed-off-by: John Keeping <john@xxxxxxxxxxxx> > > > > > Reviewed-by: Chris Zhong <zyw@xxxxxxxxxxxxxx> > > > > > --- > > > > > v3: > > > > > - Add Chris' Reviewed-by > > > > > Unchanged in v2 > > > > > > > > > > drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 9 +++++++-- > > > > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > > > > > index 4be1ff3a42bb..2e6ad4591ebf 100644 > > > > > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > > > > > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > > > > > @@ -572,8 +572,13 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) > > > > > static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, > > > > > const struct mipi_dsi_msg *msg) > > > > > { > > > > > - const u16 *tx_buf = msg->tx_buf; > > > > > - u32 val = GEN_HDATA(*tx_buf) | GEN_HTYPE(msg->type); > > > > > + const u8 *tx_buf = msg->tx_buf; > > > > > + u32 val = GEN_HTYPE(msg->type); > > > > > + > > > > > + if (msg->tx_len > 0) > > > > > + val |= GEN_HDATA(tx_buf[0]); > > > > > + if (msg->tx_len > 1) > > > > > + val |= GEN_HDATA(tx_buf[1] << 8); > > > > > > > > You should probably update the mask inside GEN_HDATA to mask off 8 bits instead of > > > > 16. > > > > > > Won't that mask off the data written by "tx_buf[1] << 8"? > > > > I would move the shift outside the mask, ie: > > > > val |= GEN_HDATA(tx_buf[1]) << 8; > > I can do that, but that doesn't seem to match the intention of the > macros which are about encoding the placement and size of fields within > registers. > > Maybe it would be clearer to do: > > u16 data = 0; > > if (msg->tx_len > 0) > data |= tx_buf[0]; > if (msg->tx_len > 1) > data |= tx_buf[1]; Yep, this looks good to me, but I think you need: data |= tx_buf[1] << 8; Sean > > val = GEN_HDATA(data) | GEN_HTYPE(msg->type); > > ? > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Sean Paul, Software Engineer, Google / Chromium OS _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel