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 <[email protected]>
Reviewed-by: Jernej Skrabec <[email protected]>
---
v2:
- use ALIGN
- add tags
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 7f13f4d715bf..840fad1b68dd 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -889,7 +889,7 @@ 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;
@@ -900,7 +900,7 @@ 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);
--
2.28.0
On Fri, Aug 28, 2020 at 02:50:32PM +0200, Ondrej Jirman wrote:
> 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 <[email protected]>
> Reviewed-by: Jernej Skrabec <[email protected]>
Applied, thanks
Maxime