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authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-05-10 07:19:23 -0400
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-05-10 07:19:23 -0400
commit71db1cd7ff4ea3b525ae7d9c97633ea281b7d981 (patch)
tree53ff3b8ecfc2869ec919e3423d69e07ddfaddd9a /drivers/tty/n_gsm.c
parent7d95fb746c4eece67308f1642a666ea1ebdbd2cc (diff)
parent75bc37fefc4471e718ba8e651aa74673d4e0a9eb (diff)
Merge tag 'v4.17-rc4' into patchwork
Linux 4.17-rc4 * tag 'v4.17-rc4': (920 commits) Linux 4.17-rc4 KVM: x86: remove APIC Timer periodic/oneshot spikes genksyms: fix typo in parse.tab.{c,h} generation rules kbuild: replace hardcoded bison in cmd_bison_h with $(YACC) gcc-plugins: fix build condition of SANCOV plugin MAINTAINERS: Update Kbuild entry with a few paths Revert "usb: host: ehci: Use dma_pool_zalloc()" platform/x86: Kconfig: Fix dell-laptop dependency chain. platform/x86: asus-wireless: Fix NULL pointer dereference arm64: vgic-v2: Fix proxying of cpuif access KVM: arm/arm64: vgic_init: Cleanup reference to process_maintenance KVM: arm64: Fix order of vcpu_write_sys_reg() arguments MAINTAINERS & files: Canonize the e-mails I use at files media: imx-media-csi: Fix inconsistent IS_ERR and PTR_ERR tools: power/acpi, revert to LD = gcc bdi: Fix oops in wb_workfn() RDMA/cma: Do not query GID during QP state transition to RTR IB/mlx4: Fix integer overflow when calculating optimal MTT size IB/hfi1: Fix memory leak in exception path in get_irq_affinity() IB/{hfi1, rdmavt}: Fix memory leak in hfi1_alloc_devdata() upon failure ...
Diffstat (limited to 'drivers/tty/n_gsm.c')
-rw-r--r--drivers/tty/n_gsm.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 3b3e1f6632d7..1dbe27c9946c 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -121,6 +121,9 @@ struct gsm_dlci {
struct mutex mutex;
/* Link layer */
+ int mode;
+#define DLCI_MODE_ABM 0 /* Normal Asynchronous Balanced Mode */
+#define DLCI_MODE_ADM 1 /* Asynchronous Disconnected Mode */
spinlock_t lock; /* Protects the internal state */
struct timer_list t1; /* Retransmit timer for SABM and UA */
int retries;
@@ -1364,7 +1367,13 @@ retry:
ctrl->data = data;
ctrl->len = clen;
gsm->pending_cmd = ctrl;
- gsm->cretries = gsm->n2;
+
+ /* If DLCI0 is in ADM mode skip retries, it won't respond */
+ if (gsm->dlci[0]->mode == DLCI_MODE_ADM)
+ gsm->cretries = 1;
+ else
+ gsm->cretries = gsm->n2;
+
mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
gsm_control_transmit(gsm, ctrl);
spin_unlock_irqrestore(&gsm->control_lock, flags);
@@ -1472,6 +1481,7 @@ static void gsm_dlci_t1(struct timer_list *t)
if (debug & 8)
pr_info("DLCI %d opening in ADM mode.\n",
dlci->addr);
+ dlci->mode = DLCI_MODE_ADM;
gsm_dlci_open(dlci);
} else {
gsm_dlci_close(dlci);
@@ -2861,11 +2871,22 @@ static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk)
static int gsm_carrier_raised(struct tty_port *port)
{
struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+ struct gsm_mux *gsm = dlci->gsm;
+
/* Not yet open so no carrier info */
if (dlci->state != DLCI_OPEN)
return 0;
if (debug & 2)
return 1;
+
+ /*
+ * Basic mode with control channel in ADM mode may not respond
+ * to CMD_MSC at all and modem_rx is empty.
+ */
+ if (gsm->encoding == 0 && gsm->dlci[0]->mode == DLCI_MODE_ADM &&
+ !dlci->modem_rx)
+ return 1;
+
return dlci->modem_rx & TIOCM_CD;
}