Messages in this thread Patch in this message | | | From | Gregory CLEMENT <> | Subject | [PATCH 3/3] tty: n_gsm: Fix waking up upper tty layer when room available | Date | Thu, 30 Apr 2020 13:34:33 +0200 |
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Warn the upper layer when n_gms is ready to receive data again. Without this the associated virtual tty remain blocked indefinitely.
Fixes: 96fd7ce58ffb ("TTY: create drivers/tty and move the tty core files there") Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> --- drivers/tty/n_gsm.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 58950b33e5ac..4ff2b981aa7e 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -665,10 +665,12 @@ static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, * FIXME: lock against link layer control transmissions */ -static void gsm_data_kick(struct gsm_mux *gsm) +static void gsm_data_kick(struct gsm_mux *gsm, struct gsm_dlci *dlci) { struct gsm_msg *msg, *nmsg; int len; + struct tty_struct *tty_dlci = NULL; + list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) { if (gsm->constipated && msg->addr) @@ -697,6 +699,29 @@ static void gsm_data_kick(struct gsm_mux *gsm) list_del(&msg->list); kfree(msg); + + if (dlci) { + tty_dlci = tty_port_tty_get(&dlci->port); + if (tty_dlci) + tty_wakeup(tty_dlci); + } else { + int i = 0; + + while (i < NUM_DLCI) { + struct gsm_dlci *dlci; + + dlci = gsm->dlci[i]; + if (dlci == NULL) { + i++; + continue; + } + + tty_dlci = tty_port_tty_get(&dlci->port); + if (tty_dlci) + tty_wakeup(tty_dlci); + i++; + } + } } } @@ -748,7 +773,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) /* Add to the actual output queue */ list_add_tail(&msg->list, &gsm->tx_list); gsm->tx_bytes += msg->len; - gsm_data_kick(gsm); + gsm_data_kick(gsm, dlci); } /** @@ -1209,7 +1234,7 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, gsm_control_reply(gsm, CMD_FCON, NULL, 0); /* Kick the link in case it is idling */ spin_lock_irqsave(&gsm->tx_lock, flags); - gsm_data_kick(gsm); + gsm_data_kick(gsm, NULL); spin_unlock_irqrestore(&gsm->tx_lock, flags); break; case CMD_FCOFF: @@ -2531,7 +2556,7 @@ static void gsmld_write_wakeup(struct tty_struct *tty) /* Queue poll */ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); spin_lock_irqsave(&gsm->tx_lock, flags); - gsm_data_kick(gsm); + gsm_data_kick(gsm, NULL); if (gsm->tx_bytes < TX_THRESH_LO) { gsm_dlci_data_sweep(gsm); } -- 2.26.1
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