Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757600Ab1EKQmm (ORCPT ); Wed, 11 May 2011 12:42:42 -0400 Received: from void.printf.net ([89.145.121.20]:52738 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754595Ab1EKQmi (ORCPT ); Wed, 11 May 2011 12:42:38 -0400 From: Chris Ball To: Per Forlin Cc: linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linaro-dev@lists.linaro.org, Stefan Nilsson XK Subject: Re: [PATCH v5] sdio: optimized SDIO IRQ handling for single irq References: <1305128885-21275-1-git-send-email-per.forlin@linaro.org> <1305128885-21275-2-git-send-email-per.forlin@linaro.org> Date: Wed, 11 May 2011 12:45:01 -0400 In-Reply-To: <1305128885-21275-2-git-send-email-per.forlin@linaro.org> (Per Forlin's message of "Wed, 11 May 2011 17:48:05 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1.90 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3892 Lines: 113 Hi Per, On Wed, May 11 2011, Per Forlin wrote: > From: Stefan Nilsson XK > > If there is only 1 function interrupt registered it is possible to > improve performance by directly calling the irq handler > and avoiding the overhead of reading the CCCR registers. > > Signed-off-by: Per Forlin > Acked-by: Ulf Hansson > Reviewed-by: Nicolas Pitre > --- > drivers/mmc/core/sdio_irq.c | 33 ++++++++++++++++++++++++++++++++- > include/linux/mmc/card.h | 1 + > 2 files changed, 33 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c > index bb192f9..a0890ac 100644 > --- a/drivers/mmc/core/sdio_irq.c > +++ b/drivers/mmc/core/sdio_irq.c > @@ -31,6 +31,17 @@ static int process_sdio_pending_irqs(struct mmc_card *card) > { > int i, ret, count; > unsigned char pending; > + struct sdio_func *func; > + > + /* > + * Optimization, if there is only 1 function interrupt registered > + * call irq handler directly > + */ > + func = card->sdio_single_irq; > + if (func) { > + func->irq_handler(func); > + return 1; > + } > > ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); > if (ret) { > @@ -42,7 +53,7 @@ static int process_sdio_pending_irqs(struct mmc_card *card) > count = 0; > for (i = 1; i <= 7; i++) { > if (pending & (1 << i)) { > - struct sdio_func *func = card->sdio_func[i - 1]; > + func = card->sdio_func[i - 1]; > if (!func) { > printk(KERN_WARNING "%s: pending IRQ for " > "non-existant function\n", > @@ -186,6 +197,24 @@ static int sdio_card_irq_put(struct mmc_card *card) > return 0; > } > > +/* If there is only 1 function registered set sdio_single_irq */ > +static void sdio_single_irq_set(struct mmc_card *card) > +{ > + struct sdio_func *func; > + int i; > + > + card->sdio_single_irq = NULL; > + if ((card->host->caps & MMC_CAP_SDIO_IRQ) && > + card->host->sdio_irqs == 1) > + for (i = 0; i < card->sdio_funcs; i++) { > + func = card->sdio_func[i]; > + if (func && func->irq_handler) { > + card->sdio_single_irq = func; > + break; > + } > + } > +} > + > /** > * sdio_claim_irq - claim the IRQ for a SDIO function > * @func: SDIO function > @@ -227,6 +256,7 @@ int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) > ret = sdio_card_irq_get(func->card); > if (ret) > func->irq_handler = NULL; > + sdio_single_irq_set(func->card); > > return ret; > } > @@ -251,6 +281,7 @@ int sdio_release_irq(struct sdio_func *func) > if (func->irq_handler) { > func->irq_handler = NULL; > sdio_card_irq_put(func->card); > + sdio_single_irq_set(func->card); > } > > ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index d8dffc9..4910dec 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -191,6 +191,7 @@ struct mmc_card { > struct sdio_cccr cccr; /* common card info */ > struct sdio_cis cis; /* common tuple info */ > struct sdio_func *sdio_func[SDIO_MAX_FUNCS]; /* SDIO functions (devices) */ > + struct sdio_func *sdio_single_irq; /* SDIO function when only one IRQ active */ > unsigned num_info; /* number of info strings */ > const char **info; /* info strings */ > struct sdio_func_tuple *tuples; /* unknown common tuples */ Thanks, looks good now -- pushed to mmc-next for .40. - Chris. -- Chris Ball One Laptop Per Child -- 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/