From: Ondrej Jirman megous@megous.com
[ Upstream commit fd90e3808fd2c207560270c39b86b71af2231aa1 ]
It's writing too much data. regmap_bulk_write expects number of register sized chunks to write, not a byte sized length of the bounce buffer. Bounce buffer needs to be padded too, so that regmap_bulk_write will not read past the end of the buffer.
Fixes: 133add5b5ad4 ("drm/sun4i: Add Allwinner A31 MIPI-DSI controller support") Signed-off-by: Ondrej Jirman megous@megous.com Signed-off-by: Maxime Ripard maxime@cerno.tech Reviewed-by: Jernej Skrabec jernej.skrabec@siol.net Link: https://patchwork.freedesktop.org/patch/msgid/20200828125032.937148-1-megous... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 79eb11cd185d..9a5584efd5e7 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -761,7 +761,7 @@ static int sun6i_dsi_dcs_write_long(struct sun6i_dsi *dsi, regmap_write(dsi->regs, SUN6I_DSI_CMD_TX_REG(0), sun6i_dsi_dcs_build_pkt_hdr(dsi, msg));
- bounce = kzalloc(msg->tx_len + sizeof(crc), GFP_KERNEL); + bounce = kzalloc(ALIGN(msg->tx_len + sizeof(crc), 4), GFP_KERNEL); if (!bounce) return -ENOMEM;
@@ -772,7 +772,7 @@ static int sun6i_dsi_dcs_write_long(struct sun6i_dsi *dsi, memcpy((u8 *)bounce + msg->tx_len, &crc, sizeof(crc)); len += sizeof(crc);
- regmap_bulk_write(dsi->regs, SUN6I_DSI_CMD_TX_REG(1), bounce, len); + regmap_bulk_write(dsi->regs, SUN6I_DSI_CMD_TX_REG(1), bounce, DIV_ROUND_UP(len, 4)); regmap_write(dsi->regs, SUN6I_DSI_CMD_CTL_REG, len + 4 - 1); kfree(bounce);