On Tue, Jan 23, 2024 at 12:29:57PM -0500, Hugo Villeneuve wrote: > Hi, > I would like the following patch to be applied to the stable > kernel 6.6: > > 3837a0379533 serial: sc16is7xx: improve regmap debugfs by using one > regmap per port > > As noted in > https://lore.kernel.org/all/20231211171353.2901416-1-hugo@xxxxxxxxxxx/raw : > --------------------- > I did not originally add a "Cc: stable" tag for the above mentioned > commit, as it was intended only to improve debugging using debugfs. But > since then, I have been able to confirm that it also fixes a long > standing bug in our system where the Tx interrupt are no longer enabled > at some point when transmitting large RS-485 paquets that completely > fill the FIFO and thus require multiple and subsequent writes to the > FIFO once space in it becomes available. I have been investigating why, > but so far I haven't found the exact cause, altough I suspect it has > something to do with regmap caching... > --------------------- > > It applies cleanly and was tested on this kernel using a > custom board with a Variscite IMX8MN NANO SOM, a NewHaven LCD, and two > SC16IS752 on a SPI bus. The four UARTs are using RS-485 mode. Now queued up, thanks. greg k-h
