Patrick Georgi has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/34529 )
Change subject: soc/nvidia/tegra210: Prevent unintended sign extension ......................................................................
soc/nvidia/tegra210: Prevent unintended sign extension
The perennial problem with u16 << 16 strikes again - the u16 is implicitly promoted to an int before the shift, which will then become negative if the highest bit of the u16 was set. Normally this isn't much of a problem, but in this case tegra_dsi_writel() expects a 64 bit integer for that argument, and so it will be sign-extended to a very large unsigned integer if it is negative. Cast bytes to a u32 beforehand to prevent the implicit promotion and thus this problem.
Change-Id: Iaf0fb1040ccafafde0093e9bb192c802b86cb2ac Signed-off-by: Jacob Garber jgarber1@ualberta.ca Found-by: Coverity CID 1294800 Reviewed-on: https://review.coreboot.org/c/coreboot/+/34529 Reviewed-by: Paul Menzel paulepanter@users.sourceforge.net Reviewed-by: Julius Werner jwerner@chromium.org Tested-by: build bot (Jenkins) no-reply@coreboot.org --- M src/soc/nvidia/tegra210/dsi.c 1 file changed, 2 insertions(+), 2 deletions(-)
Approvals: build bot (Jenkins): Verified Paul Menzel: Looks good to me, but someone else must approve Julius Werner: Looks good to me, approved
diff --git a/src/soc/nvidia/tegra210/dsi.c b/src/soc/nvidia/tegra210/dsi.c index a383ff2..7d54c9e 100644 --- a/src/soc/nvidia/tegra210/dsi.c +++ b/src/soc/nvidia/tegra210/dsi.c @@ -380,8 +380,8 @@ }
tegra_dsi_writel(dsi, 0, DSI_PKT_LEN_0_1); - tegra_dsi_writel(dsi, bytes << 16, DSI_PKT_LEN_2_3); - tegra_dsi_writel(dsi, bytes << 16, DSI_PKT_LEN_4_5); + tegra_dsi_writel(dsi, (u32)bytes << 16, DSI_PKT_LEN_2_3); + tegra_dsi_writel(dsi, (u32)bytes << 16, DSI_PKT_LEN_4_5); tegra_dsi_writel(dsi, 0, DSI_PKT_LEN_6_7);
value = MIPI_DCS_WRITE_MEMORY_START << 8 |