[PATCH] staging: fbtft: fix unaligned vmem writes when txbuf is byte-offset
From: suryasaimadhu <hidden>
Date: 2026-06-25 11:02:49
Also in:
dri-devel, linux-staging, lkml
Subsystem:
fbtft framebuffer drivers, staging subsystem, the rest · Maintainers:
Andy Shevchenko, Greg Kroah-Hartman, Linus Torvalds
fbtft_write_vmem16_bus8() and fb_ra8875's write_vmem16_bus8() offset txbuf16 by one byte for a command/start prefix, then store 16-bit pixel data via txbuf16[i]. On strict-alignment architectures this can fault the same way as the write_reg path fixed in the previous patch. Use put_unaligned() for these stores. Signed-off-by: suryasaimadhu <redacted> --- drivers/staging/fbtft/fb_ra8875.c | 3 ++- drivers/staging/fbtft/fbtft-bus.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/fbtft/fb_ra8875.c b/drivers/staging/fbtft/fb_ra8875.c
index 0ab1de664..5b95b0095 100644
--- a/drivers/staging/fbtft/fb_ra8875.c
+++ b/drivers/staging/fbtft/fb_ra8875.c@@ -10,6 +10,7 @@ #include <linux/delay.h> #include <linux/gpio/consumer.h> +#include <linux/unaligned.h> #include "fbtft.h" #define DRVNAME "fb_ra8875"
@@ -262,7 +263,7 @@ static int write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len) to_copy, remain - to_copy); for (i = 0; i < to_copy; i++) - txbuf16[i] = cpu_to_be16(vmem16[i]); + put_unaligned(cpu_to_be16(vmem16[i]), &txbuf16[i]); vmem16 = vmem16 + to_copy; ret = par->fbtftops.write(par, par->txbuf.buf,
diff --git a/drivers/staging/fbtft/fbtft-bus.c b/drivers/staging/fbtft/fbtft-bus.c
index cfcf4d7e7..fc3faab7d 100644
--- a/drivers/staging/fbtft/fbtft-bus.c
+++ b/drivers/staging/fbtft/fbtft-bus.c@@ -158,7 +158,7 @@ int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len) to_copy, remain - to_copy); for (i = 0; i < to_copy; i++) - txbuf16[i] = cpu_to_be16(vmem16[i]); + put_unaligned(cpu_to_be16(vmem16[i]), &txbuf16[i]); vmem16 = vmem16 + to_copy; ret = par->fbtftops.write(par, par->txbuf.buf,
--
2.47.3