This is a note to let you know that I've just added the patch titled
drm/sun4i: Fix dsi dcs long write function
to the 5.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-sun4i-fix-dsi-dcs-long-write-function.patch
and it can be found in the queue-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3a8d5032c7aeecef6bf106542ec5326bc2673ad5
Author: Ondrej Jirman <megous@xxxxxxxxxx>
Date: Fri Aug 28 14:50:32 2020 +0200
drm/sun4i: Fix dsi dcs long write function
[ 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@xxxxxxxxxx>
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20200828125032.937148-1-megous@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index aa67cb037e9d1..32d4c3f7fc4eb 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);
