From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luis R. Rodriguez" Subject: Re: [PATCH 2/4] swait: add the missing killable swaits Date: Fri, 30 Jun 2017 00:50:03 +0200 Message-ID: <20170629225003.GU21846@wotan.suse.de> References: <20170629133530.GA14747@kroah.com> <20170629174046.GC3954@linux-80c1.suse> <20170629183339.GD3954@linux-80c1.suse> <20170629194015.GQ21846@wotan.suse.de> <20170629194455.GR21846@wotan.suse.de> <20170629135822.366fd67a@cakuba.netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170629135822.366fd67a@cakuba.netronome.com> Sender: stable-owner@vger.kernel.org To: Jakub Kicinski Cc: "Luis R. Rodriguez" , nbroeking@me.com, Linus Torvalds , Davidlohr Bueso , Thomas Gleixner , Greg KH , mfuzzey@parkeon.com, "Eric W. Biederman" , Dmitry Torokhov , Daniel Wagner , David Woodhouse , jewalt@lgsinnovations.com, rafal@milecki.pl, Arend Van Spriel , "Rafael J. Wysocki" , "Li, Yi" , atull@kernel.org, Moritz Fischer , Petr Mladek , Johannes Berg , Emmanuel Grumbach , Coel List-Id: linux-api@vger.kernel.org On Thu, Jun 29, 2017 at 01:58:22PM -0700, Jakub Kicinski wrote: > On Thu, 29 Jun 2017 21:44:55 +0200, Luis R. Rodriguez wrote: > > > Since this swake_up() --> swake_up_all() reportedly *fixed* the one wake up > > > issue it would seem this does queue [0]. That said, I don't see any simple tests > > > tools/testing/selftests/swait but then again we don't have test for regular > > > waits either... > > > > > > [0] https://bugzilla.kernel.org/show_bug.cgi?id=195477 > > > > I should also note that the swake_up_all() should have only helped in cases where > > 3 cards were used, as if only 2 were used that should have been covered by just > > the swake_up(). Unless of course I hear otherwise by the reporter, Nicolas or > > from Jakub. > > I was hitting this with 2 cards. Thanks! Thing is I'm not convinced the issue with 2 cards was the swake_up() Vs swake_up_all() in this case though. Let's recall also the missing wake up on errors! And the fact that netronome has optional firmware, which naturally can fail. So could the issue with 2 cards instead of the miss of a wake up on error due to batched requests ? If so then that still would not put blame on the swake_up()! We can find out by you testing the series I just posted [0] and if that did not fix the issue then try this patch, which I do expect to actually have fixed most issues considering optional firmware. ie, I expect the combination of both to fix your issues, not just the last series I just posted [0]. If you want this in git form you can find all of the patches bundled on the 20170629-fw-fixes-wait-v4 branch [1]. I just wrote this patch it but it seems to have not broken the tests: $ sudo tools/testing/selftests/firmware/fw_fallback.sh tools/testing/selftests/firmware/fw_fallback.sh: timeout works tools/testing/selftests/firmware/fw_fallback.sh: firmware comparison works tools/testing/selftests/firmware/fw_fallback.sh: fallback mechanism works tools/testing/selftests/firmware/fw_fallback.sh: cancelling fallback mechanism works tools/testing/selftests/firmware/fw_fallback.sh: custom fallback loading mechanism works tools/testing/selftests/firmware/fw_fallback.sh: cancelling custom fallback mechanism works tools/testing/selftests/firmware/fw_fallback.sh: SIGCHLD on sync ignored as expected $ sudo tools/testing/selftests/firmware/fw_filesystem.sh tools/testing/selftests/firmware/fw_filesystem.sh: timeout works tools/testing/selftests/firmware/fw_filesystem.sh: filesystem loading works tools/testing/selftests/firmware/fw_filesystem.sh: async filesystem loading works [0] https://lkml.kernel.org/r/20170629205151.5329-1-mcgrof@kernel.org [1] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20170629-fw-fixes-wait-v4 Luis >>From cb7fee12c6d539405793e883dfd79e0b21c2baad Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Thu, 29 Jun 2017 15:19:04 -0700 Subject: [RFT] firmware: send wake up on failure for batched requests Fix batched requests from waiting forever on failure. The firmware API supports "batched requests" which means requests with the same name share the same lookup effort. They wait for the first request to complete, however they are set to always wait for what seem to be forever (MAX_SCHEDULE_TIMEOUT). We currently handle informing waited batched requests on success but we never seem to have sent smoke signals of any kind on failure! This should mean secondary requests batched in seem to just wait forever when the request fails. For device drivers with optional firmware schemes (Intel, or Netronome), this could mean that when you boot a system with multiple cards the firmware will seem to never load on the system, or that the card is just not responsive even the driver initialized. Due to differences in scheduling possible this should not always trigger, so triggering batched requests actually needs to be triggered for this to be an issue. Its reported that at least with the Intel WiFi cards on one system this issue was creeping up 50% of the boots [0]. [0] https://bugzilla.kernel.org/show_bug.cgi?id=195477 Reported-by: Nicolas Reported-by: John Ewalt Reported-by: Jakub Kicinski Signed-off-by: Luis R. Rodriguez --- drivers/base/firmware_class.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index d3d071dbd2a5..40d1351660c0 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -152,28 +152,27 @@ static void __fw_state_set(struct fw_state *fw_st, __fw_state_set(fw_st, FW_STATUS_LOADING) #define fw_state_done(fw_st) \ __fw_state_set(fw_st, FW_STATUS_DONE) +#define fw_state_aborted(fw_st) \ + __fw_state_set(fw_st, FW_STATUS_ABORTED) #define fw_state_wait(fw_st) \ __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT) -#ifndef CONFIG_FW_LOADER_USER_HELPER - -#define fw_state_is_aborted(fw_st) false - -#else /* CONFIG_FW_LOADER_USER_HELPER */ - static int __fw_state_check(struct fw_state *fw_st, enum fw_status status) { return fw_st->status == status; } +#define fw_state_is_aborted(fw_st) \ + __fw_state_check(fw_st, FW_STATUS_ABORTED) + +#ifdef CONFIG_FW_LOADER_USER_HELPER + #define fw_state_aborted(fw_st) \ __fw_state_set(fw_st, FW_STATUS_ABORTED) #define fw_state_is_done(fw_st) \ __fw_state_check(fw_st, FW_STATUS_DONE) #define fw_state_is_loading(fw_st) \ __fw_state_check(fw_st, FW_STATUS_LOADING) -#define fw_state_is_aborted(fw_st) \ - __fw_state_check(fw_st, FW_STATUS_ABORTED) #define fw_state_wait_timeout(fw_st, timeout) \ __fw_state_wait_common(fw_st, timeout) @@ -332,6 +331,7 @@ static struct firmware_buf *__fw_lookup_buf(const char *fw_name) return NULL; } +/* Returns 1 for batching firmware requests with the same name */ static int fw_lookup_and_allocate_buf(const char *fw_name, struct firmware_cache *fwc, struct firmware_buf **buf, void *dbuf, @@ -345,6 +345,7 @@ static int fw_lookup_and_allocate_buf(const char *fw_name, kref_get(&tmp->ref); spin_unlock(&fwc->lock); *buf = tmp; + /* requests are batched ! */ return 1; } tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size); @@ -1200,6 +1201,28 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name, return 1; /* need to load */ } +/* + * Batched requests need only one wake, we need to do this step last due to the + * fallback mechanism. The buf is protected with kref_get(), and it won't be + * released until the last user calls release_firmware(). + * + * Failed batched requests are possible as well, in such cases we just share + * the struct firmware_buf and won't release it until all requests are woken + * and have gone through this same path. + */ +static void fw_abort_batch_reqs(struct firmware *fw) +{ + struct firmware_buf *buf; + + /* Loaded directly? */ + if (!fw || !fw->priv) + return; + + buf = fw->priv; + if (!fw_state_is_aborted(&buf->fw_st)) + fw_state_aborted(&buf->fw_st); +} + /* called from request_firmware() and request_firmware_work_func() */ static int _request_firmware(const struct firmware **firmware_p, const char *name, @@ -1243,6 +1266,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name, out: if (ret < 0) { + fw_abort_batch_reqs(fw); release_firmware(fw); fw = NULL; } -- 2.11.0