Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754927Ab1EDQGT (ORCPT ); Wed, 4 May 2011 12:06:19 -0400 Received: from mail-ew0-f46.google.com ([209.85.215.46]:35764 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754661Ab1EDQGR (ORCPT ); Wed, 4 May 2011 12:06:17 -0400 From: Per Forlin To: linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linaro-dev@lists.linaro.org Cc: Chris Ball , Stefan Nilsson XK , Per Forlin Subject: [PATCH v2] sdio: optimized SDIO IRQ handling for single irq Date: Wed, 4 May 2011 18:06:01 +0200 Message-Id: <1304525161-14448-2-git-send-email-per.forlin@linaro.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1304525161-14448-1-git-send-email-per.forlin@linaro.org> References: <1304525161-14448-1-git-send-email-per.forlin@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3216 Lines: 95 From: Stefan Nilsson XK If there is only 1 function 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 --- drivers/mmc/core/sdio_irq.c | 30 ++++++++++++++++++++++++++++++ include/linux/mmc/card.h | 1 + 2 files changed, 31 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c index b300161..64c4409 100644 --- a/drivers/mmc/core/sdio_irq.c +++ b/drivers/mmc/core/sdio_irq.c @@ -32,6 +32,16 @@ static int process_sdio_pending_irqs(struct mmc_card *card) int i, ret, count; unsigned char pending; + /* + * Optimization, if there is only 1 function registered + * call irq handler directly + */ + if (card->sdio_single_irq && card->sdio_single_irq->irq_handler) { + struct sdio_func *func = card->sdio_single_irq; + func->irq_handler(func); + return 1; + } + ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); if (ret) { printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n", @@ -186,6 +196,24 @@ 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 +255,7 @@ 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 +280,7 @@ 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 adb4888..0d64211 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -145,6 +145,7 @@ 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 */ -- 1.7.4.1 -- 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/