Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932596Ab3CQPHJ (ORCPT ); Sun, 17 Mar 2013 11:07:09 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:62303 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756400Ab3CQPHG convert rfc822-to-8bit (ORCPT ); Sun, 17 Mar 2013 11:07:06 -0400 Date: Sun, 17 Mar 2013 16:06:47 +0100 From: Kevin Baradon To: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Jarod Wilson Subject: Re: [PATCH 1/2] media/rc/imon.c: make send_packet() delay configurable Message-ID: <20130317160647.6aa1c5dd@laptop-kevin.kbaradon.com> In-Reply-To: <20130314120153.7bb71ad8@redhat.com> References: <1361737170-4687-1-git-send-email-kevin.baradon@gmail.com> <1361737170-4687-2-git-send-email-kevin.baradon@gmail.com> <20130314120153.7bb71ad8@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5770 Lines: 163 Le Thu, 14 Mar 2013 12:01:53 -0300, Mauro Carvalho Chehab a écrit : > Em Sun, 24 Feb 2013 21:19:29 +0100 > Kevin Baradon escreveu: > > > Some imon devices (like 15c2:0036) need a higher delay between send_packet calls. > > Default value is still 5ms to avoid regressions on already working hardware. > > > > Also use interruptible wait to avoid load average going too high (and let caller handle signals). > > > > Signed-off-by: Kevin Baradon > > --- > > drivers/media/rc/imon.c | 14 +++++++++++--- > > 1 file changed, 11 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c > > index 78d109b..a3e66a0 100644 > > --- a/drivers/media/rc/imon.c > > +++ b/drivers/media/rc/imon.c > > @@ -347,6 +347,11 @@ module_param(pad_stabilize, int, S_IRUGO | S_IWUSR); > > MODULE_PARM_DESC(pad_stabilize, "Apply stabilization algorithm to iMON PAD " > > "presses in arrow key mode. 0=disable, 1=enable (default)."); > > > > +static unsigned int send_packet_delay = 5; > > +module_param(send_packet_delay, uint, S_IRUGO | S_IWUSR); > > +MODULE_PARM_DESC(send_packet_delay, "Minimum delay between send_packet() calls " > > + "(default 5ms)"); > > + > > Users will find a hard time discovering what delay is needed for each device. > > If this is a per-device type property, then it should, instead, be associated > with the device's USB ID. > > The better would be to encapsulate it at the USB device table, like adding a > NEED_(extra)_DELAY flag, like: > > { USB_DEVICE(0x15c2, 0x0036), .driver_info = NEED_10MS_DELAY }, > > If such flag is zero (like on all devices where .driver_info is not filled, as > Kernel zeroes the memory on all static vars), then it will keep using 5ms. > > Another alternative would be to use .driver_info for the device type, and > add a logic to handle different types with different logic. This is what > mceusb.c does, for example. > Hi, Please find below an updated patch: >From 8d4ba61cb21617b8169127b085332ed7813470c9 Mon Sep 17 00:00:00 2001 From: Kevin Baradon Date: Mon, 18 Feb 2013 18:42:47 +0100 Subject: [PATCH 1/2] media/rc/imon.c: make send_packet() delay larger for 15c2:0036 Imon device 15c2:0036 need a higher delay between send_packet() calls. Also use interruptible wait to avoid load average going too high (and let caller handle signals). Signed-off-by: Kevin Baradon --- drivers/media/rc/imon.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c index dec203b..178b946 100644 --- a/drivers/media/rc/imon.c +++ b/drivers/media/rc/imon.c @@ -112,6 +112,7 @@ struct imon_context { bool tx_control; unsigned char usb_rx_buf[8]; unsigned char usb_tx_buf[8]; + unsigned int send_packet_delay; struct tx_t { unsigned char data_buf[35]; /* user data buffer */ @@ -185,6 +186,10 @@ enum { IMON_KEY_PANEL = 2, }; +enum { + IMON_NEED_20MS_PKT_DELAY = 1 +}; + /* * USB Device ID for iMON USB Control Boards * @@ -215,7 +220,7 @@ static struct usb_device_id imon_usb_id_table[] = { /* SoundGraph iMON OEM Touch LCD (IR & 4.3" VGA LCD) */ { USB_DEVICE(0x15c2, 0x0035) }, /* SoundGraph iMON OEM VFD (IR & VFD) */ - { USB_DEVICE(0x15c2, 0x0036) }, + { USB_DEVICE(0x15c2, 0x0036), .driver_info = IMON_NEED_20MS_PKT_DELAY }, /* device specifics unknown */ { USB_DEVICE(0x15c2, 0x0037) }, /* SoundGraph iMON OEM LCD (IR & LCD) */ @@ -535,12 +540,12 @@ static int send_packet(struct imon_context *ictx) kfree(control_req); /* - * Induce a mandatory 5ms delay before returning, as otherwise, + * Induce a mandatory delay before returning, as otherwise, * send_packet can get called so rapidly as to overwhelm the device, * particularly on faster systems and/or those with quirky usb. */ - timeout = msecs_to_jiffies(5); - set_current_state(TASK_UNINTERRUPTIBLE); + timeout = msecs_to_jiffies(ictx->send_packet_delay); + set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(timeout); return retval; @@ -2335,6 +2340,10 @@ static int imon_probe(struct usb_interface *interface, } + /* default send_packet delay is 5ms but some devices need more */ + ictx->send_packet_delay = id->driver_info & IMON_NEED_20MS_PKT_DELAY ? + 20 : 5; + usb_set_intfdata(interface, ictx); if (ifnum == 0) { -- 1.7.10.4 > > /* > > * In certain use cases, mouse mode isn't really helpful, and could actually > > * cause confusion, so allow disabling it when the IR device is open. > > @@ -535,12 +540,15 @@ static int send_packet(struct imon_context *ictx) > > kfree(control_req); > > > > /* > > - * Induce a mandatory 5ms delay before returning, as otherwise, > > + * Induce a mandatory delay before returning, as otherwise, > > * send_packet can get called so rapidly as to overwhelm the device, > > * particularly on faster systems and/or those with quirky usb. > > + * Do not use TASK_UNINTERRUPTIBLE as this routine is called quite often > > + * and doing so will increase load average slightly. Caller will handle > > + * signals itself. > > */ > > - timeout = msecs_to_jiffies(5); > > - set_current_state(TASK_UNINTERRUPTIBLE); > > + timeout = msecs_to_jiffies(send_packet_delay); > > + set_current_state(TASK_INTERRUPTIBLE); > > schedule_timeout(timeout); > > > > return retval; > > Regards, > Mauro Regards, Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/