Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757632Ab2HUNGH (ORCPT ); Tue, 21 Aug 2012 09:06:07 -0400 Received: from na3sys009aog101.obsmtp.com ([74.125.149.67]:54491 "EHLO na3sys009aog101.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757274Ab2HUNGF (ORCPT ); Tue, 21 Aug 2012 09:06:05 -0400 Date: Tue, 21 Aug 2012 16:01:36 +0300 From: Felipe Balbi To: Felipe Balbi Cc: alan@linux.intel.com, Tony Lindgren , Kevin Hilman , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , linux-serial@vger.kernel.org, Linux Kernel Mailing List , Santosh Shilimkar , Shubhrajyoti Datta Subject: Re: [PATCH v2 00/13] OMAP Serial patches Message-ID: <20120821130134.GH10347@arwen.pp.htv.fi> Reply-To: balbi@ti.com References: <1345540555-24359-1-git-send-email-balbi@ti.com> <1345551371-18862-1-git-send-email-balbi@ti.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="wO3ULb5M+sQS9v8+" Content-Disposition: inline In-Reply-To: <1345551371-18862-1-git-send-email-balbi@ti.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8679 Lines: 249 --wO3ULb5M+sQS9v8+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Tue, Aug 21, 2012 at 03:15:58PM +0300, Felipe Balbi wrote: > Hi guys, >=20 > here's a series of cleanup patches to the OMAP serial > driver. A later series could be made re-implementing > DMA using the DMA Engine API. Note that for RX DMA > we could be using RX Timeout IRQ as a hint that we better > use PIO instead ;-) >=20 > All patches were tested on my pandaboard, but I'd really > like to receive Tested-by on other platforms. >=20 > After this goes in, I'll probably try to get UART wakeup > working again and only after that look at DMA. >=20 > Changes since v1: >=20 > . improved commit log on patch 9/13 (formerly 10/13) > . removed patch 2/13 > . added a new patch switching from spin_lock_irqsave() to spin_lock and > spin_unlock_irqrestore to spin_unlock >=20 > Retested with my pandaboard, UART continues to work: >=20 > # grep -i uart /proc/interrupts > 106: 124 0 GIC OMAP UART2 > # grep -i uart /proc/interrupts > 106: 189 0 GIC OMAP UART2 > # grep -i uart /proc/interrupts > 106: 255 0 GIC OMAP UART2 > # grep -i uart /proc/interrupts > 106: 321 0 GIC OMAP UART2 > # grep -i uart /proc/interrupts > 106: 387 0 GIC OMAP UART2 > # grep -i uart /proc/interrupts > 106: 453 0 GIC OMAP UART2 > # grep -i uart /proc/interrupts > 106: 519 0 GIC OMAP UART2 >=20 > cheers >=20 > ps: if anyone knows a better test for UART, let me know. >=20 > for convenience of anyone testing, patches are available on my git tree [= 1] on > branch uart >=20 > [1] git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git uart I have added one extra patch to this series: =46rom 6921efdb13dda7af216b331bb35535d4b53f004a Mon Sep 17 00:00:00 2001 =46rom: Felipe Balbi Date: Tue, 21 Aug 2012 15:48:35 +0300 Subject: [PATCH] serial: omap: drop pm_runtime_irq_safe() usage pm_runtime_irq_safe() will essentially do an unbalanced pm_runtime_get_sync() on our parent device, which might cause problems when trying to suspend. In order to prevent that we drop pm_runtime_irq_safe usage in exchange for a little performance hit when we enter our IRQ handler while still suspended. If that happens, what we will do is set the irq_pending flag, do an asynchronous pm_runtime_get() call and return IRQ_HANDLED. When our runtime_resume() callback is executed, we check for that flag, and run our IRQ handler so that we receive/transmit the pending characters. Signed-off-by: Felipe Balbi --- One extra patch to OMAP UART driver. This seems to be working pretty well even after echo mem > /sys/power/state. I can see that I can even wake my pandaboard up by sending a character through serial: # echo mem > /sys/power/state [ 1335.679260] PM: Syncing filesystems ... done. [ 1335.684387] Freezing user space processes ... (elapsed 0.00 seconds) do= ne. [ 1335.691741] Freezing remaining freezable tasks ... (elapsed 0.02 second= s) done. [ 1335.720886] Suspending console(s) (use no_console_suspend to debug) =20 [ 1335.734405] PM: suspend of devices complete after 5.492 msecs [ 1335.735534] PM: late suspend of devices complete after 1.128 msecs [ 1335.737518] PM: noirq suspend of devices complete after 1.952 msecs [ 1335.737518] Disabling non-boot CPUs ... [ 1335.738525] CPU1: shutdown [ 1338.543762] Successfully put all powerdomains to target state [ 1338.543853] Enabling non-boot CPUs ... [ 1338.545654] CPU1: Booted secondary processor [ 1338.546020] CPU1 is up [ 1338.547027] PM: noirq resume of devices complete after 0.976 msecs [ 1338.548400] PM: early resume of devices complete after 0.762 msecs [ 1339.827087] PM: resume of devices complete after 1278.686 msecs [ 1339.890960] Restarting tasks ... done. # # grep -i uart /proc/interrupts 106: 3385 0 GIC OMAP UART2 # echo mem > /sys/power/state [ 1358.015624] PM: Syncing filesystems ... done. [ 1358.020812] Freezing user space processes ... (elapsed 0.00 seconds) do= ne. [ 1358.028167] Freezing remaining freezable tasks ... (elapsed 0.01 second= s) done. [ 1358.055084] Suspending console(s) (use no_console_suspend to debug) =20 [ 1358.068847] PM: suspend of devices complete after 5.633 msecs [ 1358.070007] PM: late suspend of devices complete after 1.126 msecs [ 1358.072051] PM: noirq suspend of devices complete after 2.040 msecs [ 1358.072051] Disabling non-boot CPUs ... [ 1358.073211] CPU1: shutdown [ 1359.104156] Successfully put all powerdomains to target state [ 1359.104278] Enabling non-boot CPUs ... [ 1359.106079] CPU1: Booted secondary processor [ 1359.106475] CPU1 is up [ 1359.107482] PM: noirq resume of devices complete after 1.004 msecs [ 1359.108886] PM: early resume of devices complete after 0.761 msecs [ 1360.414794] PM: resume of devices complete after 1305.836 msecs [ 1360.478668] Restarting tasks ... done. # # grep -i uart /proc/interrupts 106: 3511 0 GIC OMAP UART2 arch/arm/plat-omap/include/plat/omap-serial.h | 1 + drivers/tty/serial/omap-serial.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-= omap/include/plat/omap-serial.h index 743ac80..52328ca 100644 --- a/arch/arm/plat-omap/include/plat/omap-serial.h +++ b/arch/arm/plat-omap/include/plat/omap-serial.h @@ -130,6 +130,7 @@ struct uart_omap_port { u32 context_loss_cnt; u32 errata; u8 wakeups_enabled; + unsigned int irq_pending:1; =20 struct pm_qos_request pm_qos_request; u32 latency; diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-ser= ial.c index a79658d..7e237f3 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -353,9 +353,13 @@ static inline irqreturn_t serial_omap_irq(int irq, voi= d *dev_id) irqreturn_t ret =3D IRQ_HANDLED; int max_count =3D 256; =20 - spin_lock(&up->port.lock); - pm_runtime_get_sync(up->dev); + if (pm_runtime_suspended(up->dev)) { + up->irq_pending =3D true; + pm_runtime_get(up->dev); + return IRQ_HANDLED; + } =20 + spin_lock(&up->port.lock); do { iir =3D serial_in(up, UART_IIR); if (iir & UART_IIR_NO_INT) { @@ -400,6 +404,7 @@ static inline irqreturn_t serial_omap_irq(int irq, void= *dev_id) pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); up->port_activity =3D jiffies; + up->irq_pending =3D false; =20 return ret; } @@ -1305,7 +1310,6 @@ static int serial_omap_probe(struct platform_device *= pdev) pm_runtime_set_autosuspend_delay(&pdev->dev, omap_up_info->autosuspend_timeout); =20 - pm_runtime_irq_safe(&pdev->dev); pm_runtime_enable(&pdev->dev); pm_runtime_get_sync(&pdev->dev); =20 @@ -1416,6 +1420,9 @@ static int serial_omap_runtime_suspend(struct device = *dev) if (!up) return -EINVAL; =20 + if (up->irq_pending) + return -EBUSY; + if (!pdata) return 0; =20 @@ -1452,6 +1459,9 @@ static int serial_omap_runtime_resume(struct device *= dev) =20 up->latency =3D up->calc_latency; schedule_work(&up->qos_work); + + if (up->irq_pending) + serial_omap_irq(up->port.irq, up); } =20 return 0; --=20 1.7.12.rc3 --=20 balbi --wO3ULb5M+sQS9v8+ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQM4auAAoJEIaOsuA1yqREn7EP/3LRkWBHv7dzmDQ+CljyGavW Xhfo7zOClvwYI8RM5O2E9sDp0PL1Z51UV9eWzRi6Dw6qzY1RLpdLE+q9P2qXEyyb 64EPCiZCjgoBfDpTnJRBDildchNKrY5lkpdM56F7k1PUP5hW7y2U7BWSj95VMX6d NmTDuGvS9OOAO2JMnmHpu4Yo0YsrQjdjFtQCH2pggRqxDl7kCj1Ua9/hIEzS8z2F hccSonmglRwWqnp+ijvXtSpJKci/s4hEZUXawEMYzyT8jSukYFNJfKt17+85EbPx vte8VpP3kQPxFN0zMyGI0+XccMeMQszYiISyS/lE1VWlD1squfdUC6OV4swmC23i QFhOtVqQcurXaBev5yWnAH6n/b/sK2uLIADmj6dRx7V4j7F1LMaZdacf1kLG9bYm WIdMBKu894dux0M6Y2vRkIIz08OY51VwmwrVXIOKGEgo3DVL9n05X3Wx6CXiV+dR xANj14Fodl2shcKMdnCh1fjBaRkd3CVJNzT0vdfUohTOPMplQ9kiK68dBf3jUQA2 QpN/ErXHhYpBz6XDRe0L7Zcc5UJ83RcE0eDmy6ybR8Lvf+KiVN3X/pexawYQGNMK HtZpF+qQliB9viYfVpF8C+pjYjuh8QIEGxOj+zeeMZqs1fv4Iciz0vgMXUbcgeCU yTtwr5GEV2tdiDUwmOyk =4Y0X -----END PGP SIGNATURE----- --wO3ULb5M+sQS9v8+-- -- 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/