git: 51f3d0874f62 - main - usb: serial: propagate errors from ucom_queue_command()

The branch main has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=51f3d0874f6216907c8971c4af9d6be6c93edf7b

commit 51f3d0874f6216907c8971c4af9d6be6c93edf7b
Author:     Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2024-12-11 01:23:10 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2024-12-11 01:23:10 +0000

    usb: serial: propagate errors from ucom_queue_command()
    
    There's only one error that we can get back right now, but future
    changes will add some more cases that we need to watch out for.  Start
    by returning errors and propagating them back.
    
    Reviewed by:    kib
    Differential Revision:  https://reviews.freebsd.org/D47950
---
 sys/dev/usb/serial/usb_serial.c | 49 ++++++++++++++++++++++++++---------------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/sys/dev/usb/serial/usb_serial.c b/sys/dev/usb/serial/usb_serial.c
index 300438010c05..11a2e1078a67 100644
--- a/sys/dev/usb/serial/usb_serial.c
+++ b/sys/dev/usb/serial/usb_serial.c
@@ -151,7 +151,7 @@ static int	ucom_unit_alloc(void);
 static void	ucom_unit_free(int);
 static int	ucom_attach_tty(struct ucom_super_softc *, struct ucom_softc *);
 static void	ucom_detach_tty(struct ucom_super_softc *, struct ucom_softc *);
-static void	ucom_queue_command(struct ucom_softc *,
+static int	ucom_queue_command(struct ucom_softc *,
 		    usb_proc_callback_t *, struct termios *pt,
 		    struct usb_proc_msg *t0, struct usb_proc_msg *t1);
 static void	ucom_shutdown(struct ucom_softc *);
@@ -592,7 +592,7 @@ ucom_set_usb_mode(struct ucom_super_softc *ssc, enum usb_hc_mode usb_mode)
 	}
 }
 
-static void
+static int
 ucom_queue_command(struct ucom_softc *sc,
     usb_proc_callback_t *fn, struct termios *pt,
     struct usb_proc_msg *t0, struct usb_proc_msg *t1)
@@ -604,7 +604,7 @@ ucom_queue_command(struct ucom_softc *sc,
 
 	if (usb_proc_is_gone(&ssc->sc_tq)) {
 		DPRINTF("proc is gone\n");
-		return;         /* nothing to do */
+		return (ENXIO);         /* nothing to do */
 	}
 	/* 
 	 * NOTE: The task cannot get executed before we drop the
@@ -637,6 +637,8 @@ ucom_queue_command(struct ucom_softc *sc,
 	 */
 	if (fn == ucom_cfg_start_transfers)
 		sc->sc_last_start_xfer = &task->hdr;
+
+	return (0);
 }
 
 static void
@@ -760,9 +762,8 @@ ucom_open(struct tty *tp)
 		 * example if the device is not present:
 		 */
 		error = (sc->sc_callback->ucom_pre_open) (sc);
-		if (error) {
-			return (error);
-		}
+		if (error != 0)
+			goto out;
 	}
 	sc->sc_flag |= UCOM_FLAG_HL_READY;
 
@@ -782,14 +783,18 @@ ucom_open(struct tty *tp)
 	sc->sc_jitterbuf_in = 0;
 	sc->sc_jitterbuf_out = 0;
 
-	ucom_queue_command(sc, ucom_cfg_open, NULL,
+	error = ucom_queue_command(sc, ucom_cfg_open, NULL,
 	    &sc->sc_open_task[0].hdr,
 	    &sc->sc_open_task[1].hdr);
+	if (error != 0)
+		goto out;
 
 	/* Queue transfer enable command last */
-	ucom_queue_command(sc, ucom_cfg_start_transfers, NULL,
-	    &sc->sc_start_task[0].hdr, 
+	error = ucom_queue_command(sc, ucom_cfg_start_transfers, NULL,
+	    &sc->sc_start_task[0].hdr,
 	    &sc->sc_start_task[1].hdr);
+	if (error != 0)
+		goto out;
 
 	if (sc->sc_tty == NULL || (sc->sc_tty->t_termios.c_cflag & CNO_RTSDTR) == 0)
 		ucom_modem(tp, SER_DTR | SER_RTS, 0);
@@ -800,7 +805,8 @@ ucom_open(struct tty *tp)
 
 	ucom_status_change(sc);
 
-	return (0);
+out:
+	return (error);
 }
 
 static void
@@ -836,7 +842,7 @@ ucom_close(struct tty *tp)
 	}
 	ucom_shutdown(sc);
 
-	ucom_queue_command(sc, ucom_cfg_close, NULL,
+	(void)ucom_queue_command(sc, ucom_cfg_close, NULL,
 	    &sc->sc_close_task[0].hdr,
 	    &sc->sc_close_task[1].hdr);
 
@@ -1077,9 +1083,12 @@ ucom_line_state(struct ucom_softc *sc,
 	sc->sc_pls_set |= set_bits;
 	sc->sc_pls_clr |= clear_bits;
 
-	/* defer driver programming */
-	ucom_queue_command(sc, ucom_cfg_line_state, NULL,
-	    &sc->sc_line_state_task[0].hdr, 
+	/*
+	 * defer driver programming - we don't propagate any error from
+	 * this call because we'll catch such errors further up the call stack.
+	 */
+	(void)ucom_queue_command(sc, ucom_cfg_line_state, NULL,
+	    &sc->sc_line_state_task[0].hdr,
 	    &sc->sc_line_state_task[1].hdr);
 }
 
@@ -1236,7 +1245,7 @@ ucom_status_change(struct ucom_softc *sc)
 	}
 	DPRINTF("\n");
 
-	ucom_queue_command(sc, ucom_cfg_status_change, NULL,
+	(void)ucom_queue_command(sc, ucom_cfg_status_change, NULL,
 	    &sc->sc_status_task[0].hdr,
 	    &sc->sc_status_task[1].hdr);
 }
@@ -1310,14 +1319,18 @@ ucom_param(struct tty *tp, struct termios *t)
 	sc->sc_flag &= ~UCOM_FLAG_GP_DATA;
 
 	/* Queue baud rate programming command first */
-	ucom_queue_command(sc, ucom_cfg_param, t,
+	error = ucom_queue_command(sc, ucom_cfg_param, t,
 	    &sc->sc_param_task[0].hdr,
 	    &sc->sc_param_task[1].hdr);
+	if (error != 0)
+		goto done;
 
 	/* Queue transfer enable command last */
-	ucom_queue_command(sc, ucom_cfg_start_transfers, NULL,
-	    &sc->sc_start_task[0].hdr, 
+	error = ucom_queue_command(sc, ucom_cfg_start_transfers, NULL,
+	    &sc->sc_start_task[0].hdr,
 	    &sc->sc_start_task[1].hdr);
+	if (error != 0)
+		goto done;
 
 	if (t->c_cflag & CRTS_IFLOW) {
 		sc->sc_flag |= UCOM_FLAG_RTS_IFLOW;