Re: [RFC] Keeping send-delay for all RS232 ttys only?
Hi Aleksander, Il giorno mar 4 mag 2021 alle ore 00:34 Aleksander Morgado ha scritto: > > Hey Dan & all, > > The send-delay property allows us to send the characters in an AT > command one by one, with some delay in between them. Right now the > default configuration of the send-delay property is 100ms unless > explicitly disabled, as it's done in several plugins. > > I'm wondering whether it makes sense to keep this logic as it is, or > change the defaults a bit; e.g. we could keep the logic for plain > RS232 modems but assume that all USB/PCI modems will be fine without > the send delay. > > What do you all think? > I agree, USB modems should be working fine without the send delay. > P.S. this comes in the context of this bug, which to me is due to a > firmware issue or limitation, but anyway: > https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/354 > Odd, I did not see this with FN980: wondering if this is something related to a specific Qualcomm baseline... Regards, Daniele > -- > Aleksander > https://aleksander.es > ___ > ModemManager-devel mailing list > ModemManager-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel ___ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
Re: [RFC] Keeping send-delay for all RS232 ttys only?
Hey Giacinto, > 100ms between characters seems excessive. > In general there are the RTS/CTS on the serial line and on the virtual > serial over usb (supported by option and acm drivers) for this. > A stripped down RS232 with only TX/RX/GND could need some delay, but > it is very difficult to guess how much: in this case it would be > better to have it as a parameter. > Allowing to change it with udev tags seems an option, while keeping the same default value for old RS232 modems. > Some modems require a different delay: between the last answer and the > following command, to have time to output some URCs in between. > At least for Cinterion modems, they don't output URCs between a > command and its response, so they must be given a chance. > The Cinterion ATC guides always specify 100ms, but it turns out that > 1-2ms are enough. > Please note that the send-delay is not the timeout in between AT commands; it's the timeout in between the characters of a given AT command; i.e. if running AT+GCAP?: "A" then 100ms, "T", then100ms, "+" then 100ms, "G" then 100ms -- Aleksander https://aleksander.es ___ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
Re: [RFC] Keeping send-delay for all RS232 ttys only?
Hi Aleksander, 100ms between characters seems excessive. In general there are the RTS/CTS on the serial line and on the virtual serial over usb (supported by option and acm drivers) for this. A stripped down RS232 with only TX/RX/GND could need some delay, but it is very difficult to guess how much: in this case it would be better to have it as a parameter. Some modems require a different delay: between the last answer and the following command, to have time to output some URCs in between. At least for Cinterion modems, they don't output URCs between a command and its response, so they must be given a chance. The Cinterion ATC guides always specify 100ms, but it turns out that 1-2ms are enough. Regards, Giacinto On Tue, May 4, 2021 at 12:34 AM Aleksander Morgado wrote: > > Hey Dan & all, > > The send-delay property allows us to send the characters in an AT > command one by one, with some delay in between them. Right now the > default configuration of the send-delay property is 100ms unless > explicitly disabled, as it's done in several plugins. > > I'm wondering whether it makes sense to keep this logic as it is, or > change the defaults a bit; e.g. we could keep the logic for plain > RS232 modems but assume that all USB/PCI modems will be fine without > the send delay. > > What do you all think? > > P.S. this comes in the context of this bug, which to me is due to a > firmware issue or limitation, but anyway: > https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/354 > > -- > Aleksander > https://aleksander.es > ___ > ModemManager-devel mailing list > ModemManager-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel ___ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
[RFC] Keeping send-delay for all RS232 ttys only?
Hey Dan & all, The send-delay property allows us to send the characters in an AT command one by one, with some delay in between them. Right now the default configuration of the send-delay property is 100ms unless explicitly disabled, as it's done in several plugins. I'm wondering whether it makes sense to keep this logic as it is, or change the defaults a bit; e.g. we could keep the logic for plain RS232 modems but assume that all USB/PCI modems will be fine without the send delay. What do you all think? P.S. this comes in the context of this bug, which to me is due to a firmware issue or limitation, but anyway: https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/354 -- Aleksander https://aleksander.es ___ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
