From: "Gabriel L. Somlo" <gsomlo@gmail.com>
To: Jiri Slaby <jirislaby@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
gregkh@linuxfoundation.org, kgugala@antmicro.com,
mholenko@antmicro.com, joel@jms.id.au,
david.abdurachmanov@gmail.com, florent@enjoy-digital.fr,
geert@linux-m68k.org, ilpo.jarvinen@linux.intel.com
Subject: Re: [PATCH v5 13/14] serial: liteuart: add IRQ support for the TX path
Date: Mon, 21 Nov 2022 09:07:35 -0500 [thread overview]
Message-ID: <Y3uGJ3D4OH0vPLqj@errol.ini.cmu.edu> (raw)
In-Reply-To: <7e2e76f8-5d88-4df4-2335-9f7b129b2e26@kernel.org>
On Mon, Nov 21, 2022 at 09:58:41AM +0100, Jiri Slaby wrote:
> On 18. 11. 22, 15:55, Gabriel Somlo wrote:
> > Switch the TX path to IRQ-driven operation, while maintaining support
> > for polling mode via the poll timer.
> >
> > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
> > Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> ...
> > @@ -154,6 +148,8 @@ static irqreturn_t liteuart_interrupt(int irq, void *data)
> > isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg;
> > if (isr & EV_RX)
> > liteuart_rx_chars(port);
> > + if (isr & EV_TX)
> > + liteuart_tx_chars(port);
>
> Wait, how do you ensure the OFF_EV_PENDING reg contains EV_RX and/or EV_TX
> in the polling mode?
The hardware (well, *gateware*) is coded to populate the EV_PENDING
register regardless of whether IRQs are enabled via the EV_ENABLE
register (or indeed, whether IRQs are even "wired into" the design at
all). See
https://github.com/enjoy-digital/litex/blob/master/litex/soc/cores/uart.py
and
https://github.com/enjoy-digital/litex/blob/master/litex/soc/interconnect/csr_eventmanager.py
for a starting point on why it's OK to just assume that...
Thanks,
--Gabriel
next prev parent reply other threads:[~2022-11-21 14:11 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-18 14:54 [PATCH v5 00/14] serial: liteuart: add IRQ support Gabriel Somlo
2022-11-18 14:54 ` [PATCH v5 01/14] serial: liteuart: use KBUILD_MODNAME as driver name Gabriel Somlo
2022-11-21 9:45 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 02/14] serial: liteuart: use bit number macros Gabriel Somlo
2022-11-21 9:45 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 03/14] serial: liteuart: remove unused uart_ops stubs Gabriel Somlo
2022-11-21 9:49 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 04/14] serial: liteuart: don't set unused port fields Gabriel Somlo
2022-11-21 9:53 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 05/14] serial: liteuart: minor style fix in liteuart_init() Gabriel Somlo
2022-11-21 9:53 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 06/14] serial: liteuart: move tty_flip_buffer_push() out of rx loop Gabriel Somlo
2022-11-21 9:55 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 07/14] serial: liteuart: rx loop should only ack rx events Gabriel Somlo
2022-11-18 14:55 ` [PATCH v5 08/14] serial: liteuart: simplify passing of uart_insert_char() flag Gabriel Somlo
2022-11-21 9:56 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 09/14] serial: liteuart: fix rx loop variable types Gabriel Somlo
2022-11-21 8:37 ` Jiri Slaby
2022-11-21 8:42 ` Jiri Slaby
2022-11-21 8:45 ` Jiri Slaby
2022-11-21 13:55 ` Gabriel L. Somlo
2022-11-22 7:37 ` Jiri Slaby
2022-11-22 21:05 ` Gabriel L. Somlo
2022-11-23 5:39 ` Jiri Slaby
2022-11-18 14:55 ` [PATCH v5 10/14] serial: liteuart: separate rx loop from poll timer Gabriel Somlo
2022-11-21 10:16 ` Geert Uytterhoeven
2022-11-21 16:44 ` Gabriel L. Somlo
2022-11-18 14:55 ` [PATCH v5 11/14] serial: liteuart: move function definitions Gabriel Somlo
2022-11-21 10:17 ` Geert Uytterhoeven
2022-11-18 14:55 ` [PATCH v5 12/14] serial: liteuart: add IRQ support for the RX path Gabriel Somlo
2022-11-21 8:54 ` Jiri Slaby
2022-11-21 18:50 ` Gabriel L. Somlo
2022-11-22 7:44 ` Jiri Slaby
2022-11-22 9:54 ` Geert Uytterhoeven
2022-11-22 19:41 ` Gabriel L. Somlo
2022-11-18 14:55 ` [PATCH v5 13/14] serial: liteuart: add IRQ support for the TX path Gabriel Somlo
2022-11-21 8:58 ` Jiri Slaby
2022-11-21 14:07 ` Gabriel L. Somlo [this message]
2022-11-18 14:55 ` [PATCH v5 14/14] serial: liteuart: move polling putchar() function Gabriel Somlo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y3uGJ3D4OH0vPLqj@errol.ini.cmu.edu \
--to=gsomlo@gmail.com \
--cc=david.abdurachmanov@gmail.com \
--cc=florent@enjoy-digital.fr \
--cc=geert@linux-m68k.org \
--cc=gregkh@linuxfoundation.org \
--cc=ilpo.jarvinen@linux.intel.com \
--cc=jirislaby@kernel.org \
--cc=joel@jms.id.au \
--cc=kgugala@antmicro.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=mholenko@antmicro.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).