| Message ID | 20170121163128.22240-12-john@metanate.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi John Reviewed-by: Chris Zhong <zyw@rock-chips.com> On 01/22/2017 12:31 AM, John Keeping wrote: > By dereferencing the MIPI command buffer as a u32* we rely on it being > correctly aligned on ARM, but this may not be the case. Copy it into a > stack variable that will be correctly aligned. > > Signed-off-by: John Keeping <john@metanate.com> > --- > Unchanged in v2 > --- > drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > index 03fc096fe1bd..ddbc037e7ced 100644 > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > @@ -607,10 +607,10 @@ static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, > static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, > const struct mipi_dsi_msg *msg) > { > - const u32 *tx_buf = msg->tx_buf; > - int len = msg->tx_len, pld_data_bytes = sizeof(*tx_buf), ret; > + const u8 *tx_buf = msg->tx_buf; > + int len = msg->tx_len, pld_data_bytes = sizeof(u32), ret; > u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type); > - u32 remainder = 0; > + u32 remainder; > u32 val; > > if (msg->tx_len < 3) { > @@ -621,12 +621,14 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, > > while (DIV_ROUND_UP(len, pld_data_bytes)) { > if (len < pld_data_bytes) { > + remainder = 0; > memcpy(&remainder, tx_buf, len); > dsi_write(dsi, DSI_GEN_PLD_DATA, remainder); > len = 0; > } else { > - dsi_write(dsi, DSI_GEN_PLD_DATA, *tx_buf); > - tx_buf++; > + memcpy(&remainder, tx_buf, pld_data_bytes); > + dsi_write(dsi, DSI_GEN_PLD_DATA, remainder); > + tx_buf += pld_data_bytes; > len -= pld_data_bytes; > } >
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index 03fc096fe1bd..ddbc037e7ced 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -607,10 +607,10 @@ static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, const struct mipi_dsi_msg *msg) { - const u32 *tx_buf = msg->tx_buf; - int len = msg->tx_len, pld_data_bytes = sizeof(*tx_buf), ret; + const u8 *tx_buf = msg->tx_buf; + int len = msg->tx_len, pld_data_bytes = sizeof(u32), ret; u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type); - u32 remainder = 0; + u32 remainder; u32 val; if (msg->tx_len < 3) { @@ -621,12 +621,14 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, while (DIV_ROUND_UP(len, pld_data_bytes)) { if (len < pld_data_bytes) { + remainder = 0; memcpy(&remainder, tx_buf, len); dsi_write(dsi, DSI_GEN_PLD_DATA, remainder); len = 0; } else { - dsi_write(dsi, DSI_GEN_PLD_DATA, *tx_buf); - tx_buf++; + memcpy(&remainder, tx_buf, pld_data_bytes); + dsi_write(dsi, DSI_GEN_PLD_DATA, remainder); + tx_buf += pld_data_bytes; len -= pld_data_bytes; }
By dereferencing the MIPI command buffer as a u32* we rely on it being correctly aligned on ARM, but this may not be the case. Copy it into a stack variable that will be correctly aligned. Signed-off-by: John Keeping <john@metanate.com> --- Unchanged in v2 --- drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)