Hi Fabio, On 23 May 2017 17:26 Fabio Estevam wrote: > Subject: Re: [PATCH V1] serial: imx: revert setup DCEDTE early and ensure DCD and RI irqs to be off > On Tue, May 23, 2017 at 9:17 AM, Steve Twiss wrote: > > > > Revert the commit e61c38d85b7392e ("serial: imx: setup DCEDTE early and > > ensure DCD and RI irqs to be off") > > > > The patch submitted to setup DCEDTE early and ensure DCD and RI irqs to > > be off, causes a serial console display problem the i.MX6Q SABRESD board. > > The console becomes unreadable and unwritable. > > > > Tested-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx> > > Signed-off-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx> > > > > --- > > This patch applies against linux-next and v4.12-rc2 > > > > Hi, > > > > I have been seeing a problem with the serial output console on the i.MX6Q > > SABRESD, but not the i.MX6DL SABRESD. Everything was fine up to > > linux-mainline/v4.11 but changed after linux-next/next-20170501. > > > > Some bisection has pointed at the commit > > e61c38d85b7392e033ee03bca46f1d6006156175 which, once removed from my > > linux-next/v4.12-rc2 build allows the i.MX6Q board to display the console > > correctly again. > > > > This patch removes the original commit e61c38d85b7392e ("serial: imx: > > setup DCEDTE early and ensure DCD and RI irqs to be off") from linux-next > > v4.12-rc2 and fixes the serial problem seen in the i.MX6Q SABRESD board. > > How can the error be reproduced? > > Care to share more details of the error, please? 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) CPU: Freescale i.MX6 family TO1.2 at 792 MHz Thermal sensor with ratio = 200 Temperature: 46 C, calibration data 0x5f15527d mx6q pll1: 792MHz mx6q pll2: 528MHz mx6q pll3: 480MHz mx6q pll8: 50MHz ipg clock : 66000000Hz ipg per clock : 66000000Hz uart clock : 80000000Hz cspi clock : 60000000Hz ahb clock : 132000000Hz axi clock : 264000000Hz emi_slow clock: 132000000Hz ddr clock : 528000000Hz usdhc1 clock : 198000000Hz usdhc2 clock : 198000000Hz usdhc3 clock : 198000000Hz usdhc4 clock : 198000000Hz nfc clock : 24000000Hz Board: i.MX6Q-SABRESD: unknown-board Board: 0x63012 [WDOG ] Boot Device: SD I2C: ready DRAM: 1 GB MMC: FSL_USDHC: 0,FSL_USDHC: 1,FSL_USDHC: 2,FSL_USDHC: 3 In: serial Out: serial Err: serial Found PFUZE100! deviceid=10,revid=11 Net: got MAC address from IIM: 00:04:9f:02:e3:0a FEC0 [PRIME] Hit any key to stop autoboot: 0 PHY indentify @ 0x1 = 0x004dd074 FEC: Link is Up 796d Using FEC0 device TFTP from server 192.168.2.1; our IP address is 192.168.2.2 Filename 'uImage_dtb.imx6q.v4.12-rc2'. Load address: 0x12000000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ########################################################## done Bytes transferred = 5951108 (5ace84 hex) ## Booting kernel from Legacy Image at 12000000 ... Image Name: Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 5951044 Bytes = 5.7 MB Load Address: 10800000 Entry Point: 10800000 Verifying Checksum ... OK Loading Kernel Image ... OK OK Starting kernel ... à ü ü pþ àüþü à àà àüþü àüü þü à ü à à àüŽ àü àü àà à à €à àüþü ààü üÿ à àüŽü þü àüàð ààðàà à þ ~pà œà `þ ü àüŽà à à ü à þ üþ à ü à Žàà à ààü üÿ à àüŽü þü àüàð €àà ààààðàà ðàüààüðààðààà þ üÿ üðü üŽ à üŽà à à üü þ üÿ à àü ü pð üÀ üþü ü àà àüpÿ üààðàà ðàüàð à üàŽ ~8à Žàà Žààü€ààðààüp Ž à à üà à à ààðàüðàà ðà üàpþàüðàüðààþà ðà üààà à ààðàà ðàüüàŽà €ü àà Ž üà~ÿ üàà àà ü üŽà à ü þ àü~Žüàðààðààà à þà € ü ààð ü~ÿ àüŽà àüŽü þü à ðààà Ž üà~ÿ üàŽà àü€ þ üà ðààü€ àüðààüüà€à üà €ü àà Ž àü àà ààã pŽ ààü ü þü àü àüŽ à àüþü à àà àþ àü€ ü üð àà ààã pŽ à € àü àüŽ à àüþü à à Ž ü --- 8< --- Is this enough information for you? It would be difficult to reproduce without the i.MX6Q (quad) board from Freescale/NXP I think. Regards, Steve ��.n��������+%������w��{.n�����{��ǫ����{ay�ʇڙ���f���h������_�(�階�ݢj"��������G����?���&��