From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Mon, 16 Apr 2018 14:26:53 -0700 Subject: 4.16 OMAP serial transmit corruption? In-Reply-To: <20180416154545.GA5671@atomide.com> References: <20180416151732.GU16141@n2100.armlinux.org.uk> <20180416154545.GA5671@atomide.com> Message-ID: <20180416212653.GC5671@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Tony Lindgren [180416 15:47]: > * Russell King - ARM Linux [180416 15:19]: > > Hi, > > > > I'm not entirely sure what's going on, but I see corrupted characters > > with the serial console on the OMAP4430 SDP board. During boot, > > everything seems fine, the problem appears to be userspace output. > > > > For example, if I edit a file, then quit vi: > > > > :q??%??B??Z?root at omap-4430sdp:~# > > I don't think I've seen that one. What I've seen few times is > typing a key on the serial console echoing back the previous > character typed while the new character won't get displayed > until hitting keyboard again. Only rebooting the device seems > to solve this. This is with 4430 ES2.3 revision. > > I wonder if we're missing some parts of errata i202 handling > in omap_8250_mdr1_errataset()? Trying to see what we might be missing in 8250_omap compared to omap-serial, your description sounds like it could be similar issue compared to what got fixed for omap-serial earlier with commit 0ba5f66836c9 ("tty: serial: OMAP: use a 1-byte RX FIFO threshold in PIO mode"). > Also, I'm seeing an issue where the UARTs won't idle on init > with 8250_omap driver if connected to the wl12xx bluetooth port > unless I write some data to the port first. It does not seem > to be related to the rts/cts lines being wired as I've tested > muxing them out of the way. I'll try to debug this one a bit. Regards, Tony