From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH] mfd: omap-usb-tll: Don't hold lock during pm_runtime_get/put_sync() Date: Wed, 8 Jan 2014 11:58:55 +0530 Message-ID: <52CCF027.6040607@ti.com> References: <1387360909-10624-1-git-send-email-rogerq@ti.com> <20131218103641.GD14274@lee--X1> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:52450 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752078AbaAHG3C (ORCPT ); Wed, 8 Jan 2014 01:29:02 -0500 In-Reply-To: <20131218103641.GD14274@lee--X1> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Lee Jones Cc: sameo@linux.intel.com, balbi@ti.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, stable@vger.kernel.org Hi, On 12/18/2013 04:06 PM, Lee Jones wrote: >> pm_runtime_get/put_sync() can sleep so don't hold spinlock while >> calling them. >> >> This patch prevents a BUG() when CONFIG_DEBUG_ATOMIC_SLEEP is enabled. >> Bug is present in Kernel versions v3.9 onwards. >> >> Reported-by: Tomi Valkeinen >> Signed-off-by: Roger Quadros >> Tested-by: Tomi Valkeinen >> Cc: # 3.9+ >> --- >> drivers/mfd/omap-usb-tll.c | 11 ++++++----- >> 1 file changed, 6 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c >> index 0d946ae1..248004c 100644 >> --- a/drivers/mfd/omap-usb-tll.c >> +++ b/drivers/mfd/omap-usb-tll.c >> @@ -346,7 +346,9 @@ int omap_tll_init(struct usbhs_omap_platform_data *pdata) >> for (i = 0; i < tll->nch; i++) >> needs_tll |= omap_usb_mode_needs_tll(pdata->port_mode[i]); >> >> + spin_unlock(&tll_lock); >> pm_runtime_get_sync(tll_dev); >> + spin_lock(&tll_lock); > > This is pretty ugly. Can't you move it above the spin_lock() instead? OK. I'll also remove NULL check for tll_dev outside the spin_lock(). > > > >> tll = dev_get_drvdata(tll_dev); >> >> + spin_unlock(&tll_lock); >> pm_runtime_get_sync(tll_dev); >> + spin_lock(&tll_lock); > > Same here? Yes. > >> for (i = 0; i < tll->nch; i++) { >> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) { >> @@ -438,7 +441,6 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata) >> } >> >> spin_unlock(&tll_lock); >> - > > This doesn't belong in this patch and is now inconsistent with the > other functions in the driver. OK. > >> return 0; >> } >> EXPORT_SYMBOL_GPL(omap_tll_enable); >> @@ -464,9 +466,8 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata) >> } >> } >> >> - pm_runtime_put_sync(tll_dev); >> - >> spin_unlock(&tll_lock); >> + pm_runtime_put_sync(tll_dev); >> >> return 0; >> } > cheers, -roger