From: Michal Kazior <michal.kazior@tieto.com> To: Kalle Valo <kvalo@qca.qualcomm.com> Cc: ath10k@lists.infradead.org, linux-wireless@vger.kernel.org Subject: Re: [PATCH v2] ath10k: fix device teardown Date: Fri, 2 Aug 2013 09:51:28 +0200 [thread overview] Message-ID: <CA+BoTQktaDtp=fc3C_u4geA6vK72B1X4QnsD_GqrzU9NXEmBrA@mail.gmail.com> (raw) In-Reply-To: <87bo5gpmij.fsf@kamboji.qca.qualcomm.com> On 2 August 2013 09:41, Kalle Valo <kvalo@qca.qualcomm.com> wrote: > Michal Kazior <michal.kazior@tieto.com> writes: > >> This fixes interrupt-related issue when no >> interfaces were running thus the device was >> considered powered down. >> >> The power_down() function isn't really powering >> down the device. It simply assumed it won't >> interrupt. This wasn't true in some cases and >> could lead to paging failures upon FW indication >> interrupt (i.e. FW crash) because some structures >> aren't allocated in that device state. >> >> One reason for that was that ar_pci->started >> wasn't reset. The other is interrupts should've >> been masked when teardown starts. >> >> The patch reorganized interrupt setup and makes >> sure ar_pci->started is reset accordingly. >> >> Reported-by: Ben Greear <greearb@candelatech.com> >> Signed-off-by: Michal Kazior <michal.kazior@tieto.com> >> --- >> v2: >> * updated commit message >> * added Reported-By: Ben >> * added disable_irq() in hif_stop() >> * added ar_pci->started resetting >> * removed ar_pci->intr_started > > Thanks, this looks much better now. > > But I still have one question: > >> @@ -1742,6 +1761,12 @@ static int ath10k_pci_hif_power_up(struct ath10k *ar) >> { >> int ret; >> >> + ret = ath10k_pci_start_intr(ar); >> + if (ret) { >> + ath10k_err("could not start interrupt handling (%d)\n", ret); >> + goto err; >> + } > > So now we call start_intr() during power_up(), which means that we do > the request_irq() calls during every interface up event. Does that cause > any meaningful overhead? I don't think so. > For me it looks better to do all resource allocation in > ath10k_pci_probe(), like request_irq(), and free the resources in > ath10k_pci_remove(). But then we would need to immeadiately call > disable_irq() and then enable_irq() from power_up() so I'm not sure if > that's any better. Not only that. Since disable/enable_irq must be balanced we'd need some way to track whether we have irqs enabled/disabled - either with an extra bool variable, additional ath10k_states or new pci-specific states. The patch assumes disable_irq is followed by free_irq (which it is) and possibly request_irq later on. Pozdrawiam / Best regards, Michał Kazior.
WARNING: multiple messages have this Message-ID (diff)
From: Michal Kazior <michal.kazior@tieto.com> To: Kalle Valo <kvalo@qca.qualcomm.com> Cc: linux-wireless@vger.kernel.org, ath10k@lists.infradead.org Subject: Re: [PATCH v2] ath10k: fix device teardown Date: Fri, 2 Aug 2013 09:51:28 +0200 [thread overview] Message-ID: <CA+BoTQktaDtp=fc3C_u4geA6vK72B1X4QnsD_GqrzU9NXEmBrA@mail.gmail.com> (raw) In-Reply-To: <87bo5gpmij.fsf@kamboji.qca.qualcomm.com> On 2 August 2013 09:41, Kalle Valo <kvalo@qca.qualcomm.com> wrote: > Michal Kazior <michal.kazior@tieto.com> writes: > >> This fixes interrupt-related issue when no >> interfaces were running thus the device was >> considered powered down. >> >> The power_down() function isn't really powering >> down the device. It simply assumed it won't >> interrupt. This wasn't true in some cases and >> could lead to paging failures upon FW indication >> interrupt (i.e. FW crash) because some structures >> aren't allocated in that device state. >> >> One reason for that was that ar_pci->started >> wasn't reset. The other is interrupts should've >> been masked when teardown starts. >> >> The patch reorganized interrupt setup and makes >> sure ar_pci->started is reset accordingly. >> >> Reported-by: Ben Greear <greearb@candelatech.com> >> Signed-off-by: Michal Kazior <michal.kazior@tieto.com> >> --- >> v2: >> * updated commit message >> * added Reported-By: Ben >> * added disable_irq() in hif_stop() >> * added ar_pci->started resetting >> * removed ar_pci->intr_started > > Thanks, this looks much better now. > > But I still have one question: > >> @@ -1742,6 +1761,12 @@ static int ath10k_pci_hif_power_up(struct ath10k *ar) >> { >> int ret; >> >> + ret = ath10k_pci_start_intr(ar); >> + if (ret) { >> + ath10k_err("could not start interrupt handling (%d)\n", ret); >> + goto err; >> + } > > So now we call start_intr() during power_up(), which means that we do > the request_irq() calls during every interface up event. Does that cause > any meaningful overhead? I don't think so. > For me it looks better to do all resource allocation in > ath10k_pci_probe(), like request_irq(), and free the resources in > ath10k_pci_remove(). But then we would need to immeadiately call > disable_irq() and then enable_irq() from power_up() so I'm not sure if > that's any better. Not only that. Since disable/enable_irq must be balanced we'd need some way to track whether we have irqs enabled/disabled - either with an extra bool variable, additional ath10k_states or new pci-specific states. The patch assumes disable_irq is followed by free_irq (which it is) and possibly request_irq later on. Pozdrawiam / Best regards, Michał Kazior. _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k
next prev parent reply other threads:[~2013-08-02 7:51 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-18 6:39 [PATCH] ath10k: move irq setup Michal Kazior 2013-07-18 6:39 ` Michal Kazior 2013-07-30 18:35 ` Kalle Valo 2013-07-30 18:35 ` Kalle Valo 2013-07-31 5:50 ` Michal Kazior 2013-07-31 5:50 ` Michal Kazior 2013-07-31 10:50 ` Michal Kazior 2013-07-31 10:50 ` Michal Kazior 2013-08-02 7:15 ` [PATCH v2] ath10k: fix device teardown Michal Kazior 2013-08-02 7:15 ` Michal Kazior 2013-08-02 7:41 ` Kalle Valo 2013-08-02 7:41 ` Kalle Valo 2013-08-02 7:51 ` Michal Kazior [this message] 2013-08-02 7:51 ` Michal Kazior 2013-08-02 8:00 ` Kalle Valo 2013-08-02 8:00 ` Kalle Valo 2013-08-05 16:23 ` Kalle Valo 2013-08-05 16:23 ` Kalle Valo
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