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 Reviewed-by: Chris Zhong zyw@rock-chips.com --- v3: - Add Chris' Reviewed-by 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 1b6fce2600f3..0c66e6eaf44a 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -609,10 +609,10 @@ 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) { @@ -623,12 +623,14 @@ 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; }