On 12/7/24 14:31, Greg KH wrote:
On Sat, Dec 07, 2024 at 08:12:25AM +0800, Hui Wang wrote:Recently we found the fifo_read() and fifo_write() are broken in our 5.15 and 5.4 kernels after cherry-pick the commit e635f652696e ("serial: sc16is7xx: convert from _raw_ to _noinc_ regmap functions for FIFO"), that is because the reg needs to shift if we don't cherry-pick a prerequiste commit 3837a0379533 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port"). Here fix it by shifting the reg as regmap_volatile() does. Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx> --- drivers/tty/serial/sc16is7xx.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)Why not take the proper upstream commit instead?
The prerequisite commit 3837a0379533 will introduce significant change and significant conflict if backport it to 5.15.y/5.10.y, It is more likely to bring new regression.
