On 10/2/21 10:21 am, Joel Sherrill wrote: > On Tue, Feb 9, 2021 at 5:08 PM Chris Johns <chr...@rtems.org > <mailto:chr...@rtems.org>> wrote: > > On 9/2/21 11:42 pm, Jan Sommer wrote: > > From: Kinsey Moore <kinsey.mo...@oarcorp.com > <mailto:kinsey.mo...@oarcorp.com>> > > > > The zynq-uart set_attributes implementation was configured to always > > return false which causes spconsole01 to fail. This restores the > > disabled implementation which sets the baud rate registers > > appropriately and allows spconsole01 to pass. This also expands the > > set_attributes functionality to allow setting of the stop bits, > > character width, and parity. > > Hmmm I missed this change. > > Sebastian changed the Zynq driver to return an error. Returning an error > is > correct because the attributes are not being set however we have a couple > of > design approaches clashing. > > The issue pulls right back to the Xilinx SystemZ design dialogue box. The > hardware designer has the ability to set the serial port defaults. These > settings form part of the ps7init data the FSBL paints into the hardware > very > early in the boot process. Also in this data are parallel port pin > settings, AXI > clocks, memory and more so lots of important stuff. The Xilinx bootloader > and > ones I have created (I do not know about uboot) do not touch the UART > hardware > on purpose so the system designer has control. Then in 2017 Sebastian > pushed a > change to force the baudrate to a BSP specific default. > > This is normally all OK because all Zynq designs I know of use the > default of > 115200,8,n,1 for the configuration. A problem arises when these defaults > are > varied. > > Maybe something explaining this in the user manual ... > > https://docs.rtems.org/branches/master/user/bsps/bsps-arm.html#xilinx-zynq > > <https://docs.rtems.org/branches/master/user/bsps/bsps-arm.html#xilinx-zynq> > > so we have provided information on what to change? > > > I wonder if there should be a configuration parameter for the default > settings. > At least "don't override the defaults"
I am not sure this is worth the effort. Personally I cannot see any reason anyone would move away from 115200. All designs I have see use the eval board's USB serial interface so 115200 is easy to support. I think a small fragment of user doco will work. > The other approach is not to touch the defaults in hardware and allow a > get > attributes to discover them? Does termios drivers have a low level get? I > can > see a set but no get in the zynq uart driver. > > No. This reflects termios from the POSIX perspective. Ah well that rules that option out. Chris _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
