Hey Fabio, On Wed, May 24, 2017 at 08:52:50AM -0300, Fabio Estevam wrote: > On Wed, May 24, 2017 at 7:32 AM, Steve Twiss > <stwiss.opensource@xxxxxxxxxxx> wrote: > > > The USB to UART connection gets corrupted. > > If this patch is applied to the kernel, the i.MX6 Q (quad), and only this board as far as > > we know, starts to fail. This does *not* change the i.MX6DL and other sabre boards > > have been tested on kernelci.org and do not see a problem. > > > > An NXP/Freescale SABRESD i.MX6 Q board is requred. > > > > My system for testing is to TFTP the Linux kernel over an ethernet connection. The > > U-boot executes okay and the UART is working at that point. When the kernel loads > > the console trace becomes garbled, in the sense that I get the some characters being > > output to the console, in the style of the kernel starting up, but they are not correct. > > > > I expect the kernel has started ok, but I am unable to read/write through the UART > > console because of corruptions. > > > > Console log with the output I am seeing with linux-next/v4.12-rc2 > > --- 8< --- > > U-Boot 2009.08-00001-gf65536a (Jan 12 2015 - 15:47:19) > > Thanks for your detailed explanation. > > I also have a mx6q sabresd board here, but the error did not happen > when I use a recent U-Boot version. > > I would like to use the same U-Boot version here as well to help > debugging this problem. > > Could you please let me know which 2009.08 branch you used? Is it any > one from git.freescale.com > http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/refs/heads ? The problem is that RFDIV, RXTL and TXTL are overwritten in the UFCR register. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html