Hi Jonah, Do you think this patch will work against 3.9.11? If not, I'll have to invest some time into upgrading to 3.12 which proved to be difficult given all the Broadcom-related modifications in the kernel.. Thank you! Regards, Dmitry -----Original Message----- From: Johan Hovold [mailto:jhovold@xxxxxxxxx] Sent: Tuesday, November 26, 2013 6:39 AM To: Dmitry Kunilov Cc: linux-usb@xxxxxxxxxxxxxxx Subject: Re: zte_ev not properly handling ZTE AC2726 CDMA modems On Mon, Nov 25, 2013 at 06:15:28PM -0800, Dmitry Kunilov wrote: > Hi everyone, > > As a late follow-up to the discussion that happened in June about > moving support for most ZTE CDMA devices from option.c to zte_ev.c > (where the decision was to "convert and see if anyone complains"), I'd > like to complain > :) > > We have a park of approximately thirty ZTE AC2726 EVDO modems > connected to Broadcom-based routers running Linux-mips. After recent > upgrade from ancient > 2.6.22 to relatively modern 3.9.11, all 30 are having the same > problem: pppd connects and Internet access works for 20 to 60 seconds, > then connectivity drops and pppd logs an LCP timeout. After that, pppd > is able to restart the connection and run for another 20-60 seconds. > > I did notice that these modems are now handled by zte_ev instead of > option, so I went and moved all the DEVICE_INFO's back from zte_ev.c > to option.c and also disabled zte_ev module in the kernel > configuration. After this change, the modems work just fine, like they > did on 2.6.22 - using the option driver. > > Please let me know if there is any debug info I can collect to help > resolve this issue. Would you mind trying the patch below (against v3.12)? Thanks, Johan >From a84412903e68e9e5ae4693ddd1fa7d9c780cbd28 Mon Sep 17 00:00:00 2001 From: Johan Hovold <jhovold@xxxxxxxxx> Date: Tue, 26 Nov 2013 15:26:49 +0100 Subject: [PATCH] USB: serial: zte_ev debug patch Continue to read on errors. Warn about failed reads and writes. Increase zte_ev buffer sizes. Fix race in write which could lead to (temporarily) degraded throughput (backport of fix in Greg's usb-linus branch). --- drivers/usb/serial/generic.c | 23 ++++++++--------------- drivers/usb/serial/zte_ev.c | 2 ++ 2 files changed, 10 insertions(+), 15 deletions(-) diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 1f31e6b4c251..b5d976ae1b0d 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -176,14 +176,7 @@ retry: return result; } - /* Try sending off another urb, unless in irq context (in which case - * there will be no free urb). */ - if (!in_irq()) - goto retry; - - clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags); - - return 0; + goto retry; } /** @@ -369,15 +362,15 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i, urb->actual_length); - if (urb->status) { - dev_dbg(&port->dev, "%s - non-zero urb status: %d\n", + if (!urb->status) { + usb_serial_debug_data(&port->dev, __func__, urb->actual_length, + data); + port->serial->type->process_read_urb(urb); + } else { + dev_warn(&port->dev, "%s - non-zero urb status: %d\n", __func__, urb->status); - return; } - usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data); - port->serial->type->process_read_urb(urb); - /* Throttle the device if requested by tty */ spin_lock_irqsave(&port->lock, flags); port->throttled = port->throttle_req; @@ -406,7 +399,7 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb) spin_unlock_irqrestore(&port->lock, flags); if (status) { - dev_dbg(&port->dev, "%s - non-zero urb status: %d\n", + dev_warn(&port->dev, "%s - non-zero urb status: %d\n", __func__, status); spin_lock_irqsave(&port->lock, flags); diff --git a/drivers/usb/serial/zte_ev.c b/drivers/usb/serial/zte_ev.c index fca4c752a4ed..36152e3e2605 100644 --- a/drivers/usb/serial/zte_ev.c +++ b/drivers/usb/serial/zte_ev.c @@ -307,6 +307,8 @@ static struct usb_serial_driver zio_device = { }, .id_table = id_table, .num_ports = 1, + .bulk_in_size = 2048, + .bulk_out_size = 2048, .open = zte_ev_usb_serial_open, .close = zte_ev_usb_serial_close, }; -- 1.8.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
