From: Dmitry Torokhov <dmitry.torokhov@gmail.com> To: Jason Wessel <jason.wessel@windriver.com> Cc: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, Henrik Rydberg <rydberg@euromail.se>, Greg Kroah-Hartman <gregkh@suse.de>, Alexey Dobriyan <adobriyan@gmail.com>, Kay Sievers <kay.sievers@vrfy.org>, linux-input@vger.kernel.org Subject: Re: [PATCH 23/28] keyboard, input: Add hook to input to allow low level event clear Date: Sun, 28 Feb 2010 21:04:37 -0800 [thread overview] Message-ID: <20100301050437.GE765@core.coreip.homeip.net> (raw) In-Reply-To: <4B8B3B08.7000705@windriver.com> On Sun, Feb 28, 2010 at 09:56:56PM -0600, Jason Wessel wrote: > Dmitry Torokhov wrote: > > The problem with your patch is that you end up using input_pass_event() > > which only passes events to handler, but it does not reset device state. > > This will cause loss of the first press of the same button after > > returning from kdb. input_inject_event() should do what you need. You > > just need to do it from a tasklet or, better yet (there is no > > performance issue) schedule a work on keventd so you don't deadlock > > on the event lock. It will also do all necessary locking, which is > > something you seem to be ignoring. > > > > ... > > > > > > For now I am just going to drop this patch from the series, and I think > we should pick up the continuation of the discussion on the > linux-input. The lack of this patch simply means keys can stuck down > sometimes if you go in and out of the kernel debug shell when running > X. People were able to live with this a long time in the original kdb > v4.4, so they can live with it a while longer while a solution is hashed > out to "unstick the keys". > > This will allow me to re-issue a pull request which has no patches which > are in the discussion state. > OK. > It is not obvious to me how walk through the input device list with the > right locks and then obtain the handle required to call the inject > input. It does not appear that it is possible to hold the locks while > walking through the keycode device bitmap and issue calls to inject > input. Is there any kind of input API function to obtain the device bitmaps? > There is key_down bitmap right there in keyboard.c that reflects all keys that are considered "down" as far as keyboard driver is concerned. You can use input_handler_for_each_handle() for kbd_handler to iterate through all input handles and send "up" events for all keys that keyboard.c is considering as being "down". There is no harm in sending extra "up" events for keys that are not pressed - the event will simply be ignored by input core. Hope this helps. -- Dmitry
WARNING: multiple messages have this Message-ID (diff)
From: Dmitry Torokhov <dmitry.torokhov@gmail.com> To: Jason Wessel <jason.wessel@windriver.com> Cc: Kay Sievers <kay.sievers@vrfy.org>, kgdb-bugreport@lists.sourceforge.net, Greg Kroah-Hartman <gregkh@suse.de>, linux-kernel@vger.kernel.org, Henrik Rydberg <rydberg@euromail.se>, linux-input@vger.kernel.org, torvalds@linux-foundation.org, Alexey Dobriyan <adobriyan@gmail.com> Subject: Re: [PATCH 23/28] keyboard, input: Add hook to input to allow low level event clear Date: Sun, 28 Feb 2010 21:04:37 -0800 [thread overview] Message-ID: <20100301050437.GE765@core.coreip.homeip.net> (raw) In-Reply-To: <4B8B3B08.7000705@windriver.com> On Sun, Feb 28, 2010 at 09:56:56PM -0600, Jason Wessel wrote: > Dmitry Torokhov wrote: > > The problem with your patch is that you end up using input_pass_event() > > which only passes events to handler, but it does not reset device state. > > This will cause loss of the first press of the same button after > > returning from kdb. input_inject_event() should do what you need. You > > just need to do it from a tasklet or, better yet (there is no > > performance issue) schedule a work on keventd so you don't deadlock > > on the event lock. It will also do all necessary locking, which is > > something you seem to be ignoring. > > > > ... > > > > > > For now I am just going to drop this patch from the series, and I think > we should pick up the continuation of the discussion on the > linux-input. The lack of this patch simply means keys can stuck down > sometimes if you go in and out of the kernel debug shell when running > X. People were able to live with this a long time in the original kdb > v4.4, so they can live with it a while longer while a solution is hashed > out to "unstick the keys". > > This will allow me to re-issue a pull request which has no patches which > are in the discussion state. > OK. > It is not obvious to me how walk through the input device list with the > right locks and then obtain the handle required to call the inject > input. It does not appear that it is possible to hold the locks while > walking through the keycode device bitmap and issue calls to inject > input. Is there any kind of input API function to obtain the device bitmaps? > There is key_down bitmap right there in keyboard.c that reflects all keys that are considered "down" as far as keyboard driver is concerned. You can use input_handler_for_each_handle() for kbd_handler to iterate through all input handles and send "up" events for all keys that keyboard.c is considering as being "down". There is no harm in sending extra "up" events for keys that are not pressed - the event will simply be ignored by input core. Hope this helps. -- Dmitry ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev
next prev parent reply other threads:[~2010-03-01 5:04 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-02-25 21:21 [GIT PULL] kdb / kms / early debug (1 of 2) Jason Wessel 2010-02-25 21:21 ` [PATCH 01/28] Move kernel/kgdb.c to kernel/debug/debug_core.c Jason Wessel 2010-02-25 21:21 ` [PATCH 02/28] Separate the gdbstub from the debug core Jason Wessel 2010-02-25 21:21 ` [PATCH 03/28] kgdb: eliminate kgdb_wait(), all cpus enter the same way Jason Wessel 2010-02-25 21:21 ` [PATCH 04/28] kgdb,sparc: Add in kgdb_arch_set_pc for sparc Jason Wessel 2010-02-25 21:21 ` [PATCH 05/28] kgdb,sh: update superh kgdb exception handling Jason Wessel 2010-02-25 21:21 ` [PATCH 06/28] kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin Jason Wessel 2010-02-25 21:21 ` [PATCH 07/28] kdb: core for kgdb back end (1 of 2) Jason Wessel 2010-02-25 21:21 ` Jason Wessel 2010-02-25 21:21 ` [PATCH 08/28] kdb: core for kgdb back end (2 " Jason Wessel 2010-02-25 21:21 ` Jason Wessel 2010-02-25 21:21 ` [PATCH 09/28] kgdb: core changes to support kdb Jason Wessel 2010-02-25 21:21 ` [PATCH 10/28] kgdb,8250,pl011: Return immediately from console poll Jason Wessel 2010-02-25 21:21 ` [PATCH 11/28] sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code Jason Wessel 2010-02-25 21:21 ` [PATCH 12/28] sparc,sunzilog: Add console polling support for sunzilog serial driver Jason Wessel 2010-02-25 21:21 ` [PATCH 13/28] kgdb: gdb "monitor" -> kdb passthrough Jason Wessel 2010-02-25 21:21 ` [PATCH 14/28] kgdboc,keyboard: Keyboard driver for kdb with kgdb Jason Wessel 2010-02-26 7:57 ` Dmitry Torokhov 2010-02-26 13:13 ` Jason Wessel 2010-02-27 7:59 ` Dmitry Torokhov 2010-02-28 3:42 ` Jason Wessel 2010-02-28 7:45 ` Dmitry Torokhov 2010-02-25 21:21 ` [PATCH 15/28] kgdb,docs: Update the kgdb docs to include kdb Jason Wessel 2010-02-25 21:21 ` [PATCH 16/28] kgdb: remove post_primary_code references Jason Wessel 2010-02-25 21:21 ` [PATCH 17/28] x86,kgdb: Add low level debug hook Jason Wessel 2010-02-25 21:21 ` [PATCH 18/28] powerpc,kgdb: Introduce low level trap catching Jason Wessel 2010-02-25 21:21 ` [PATCH 19/28] mips,kgdb: kdb low level trap catch and stack trace Jason Wessel 2010-02-25 21:21 ` [PATCH 20/28] kgdb: Add the ability to schedule a breakpoint via a tasklet Jason Wessel 2010-02-25 21:21 ` [PATCH 21/28] kgdboc,kdb: Allow kdb to work on a non open console port Jason Wessel 2010-02-25 21:21 ` [PATCH 22/28] printk,kdb: capture printk() when in kdb shell Jason Wessel 2010-02-25 21:21 ` [PATCH 23/28] keyboard, input: Add hook to input to allow low level event clear Jason Wessel 2010-02-26 8:03 ` Dmitry Torokhov 2010-02-26 16:06 ` Jason Wessel 2010-02-26 16:06 ` Jason Wessel 2010-02-27 7:55 ` Dmitry Torokhov 2010-03-01 3:56 ` Jason Wessel 2010-03-01 3:56 ` Jason Wessel 2010-03-01 5:04 ` Dmitry Torokhov [this message] 2010-03-01 5:04 ` Dmitry Torokhov 2010-03-01 16:49 ` Jason Wessel 2010-03-01 16:49 ` Jason Wessel 2010-03-01 18:32 ` Dmitry Torokhov 2010-03-01 19:33 ` Jason Wessel 2010-03-01 19:33 ` Jason Wessel 2010-03-03 7:39 ` Jason Wessel 2010-03-03 7:39 ` Jason Wessel 2010-02-25 21:21 ` [PATCH 24/28] debug_core,kdb: Allow the debug core to process a recursive debug entry Jason Wessel 2010-02-25 21:21 ` [PATCH 25/28] MAINTAINERS: update kgdb, kdb, and debug_core info Jason Wessel 2010-02-25 21:21 ` [PATCH 26/28] kdb,debug_core: Allow the debug core to receive a panic notification Jason Wessel 2010-02-25 21:21 ` [PATCH 27/28] kgdbts,sh: Add in breakpoint pc offset for superh Jason Wessel 2010-02-25 21:21 ` [PATCH 28/28] debug_core: Turn off tracing while in the debugger Jason Wessel -- strict thread matches above, loose matches on Subject: below -- 2010-02-12 22:35 [PATCH 0/28] kgdb, kdb proposed merge for 2.6.34 Jason Wessel 2010-02-12 22:35 ` [PATCH 23/28] keyboard, input: Add hook to input to allow low level event clear Jason Wessel
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20100301050437.GE765@core.coreip.homeip.net \ --to=dmitry.torokhov@gmail.com \ --cc=adobriyan@gmail.com \ --cc=gregkh@suse.de \ --cc=jason.wessel@windriver.com \ --cc=kay.sievers@vrfy.org \ --cc=kgdb-bugreport@lists.sourceforge.net \ --cc=linux-input@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=rydberg@euromail.se \ --cc=torvalds@linux-foundation.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.