Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933791Ab3JOWje (ORCPT ); Tue, 15 Oct 2013 18:39:34 -0400 Received: from mail-pb0-f73.google.com ([209.85.160.73]:49326 "EHLO mail-pb0-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933522Ab3JOWjc (ORCPT ); Tue, 15 Oct 2013 18:39:32 -0400 From: Doug Anderson To: Chris Ball Cc: Jaehoon Chung , Seungwon Jeon , James Hogan , Grant Grundler , Alim Akhtar , Abhilash Kesavan , Tomasz Figa , Olof Johansson , Sonny Rao , Bing Zhao , Doug Anderson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] mmc: dw_mmc: Cleanup disable of low power mode w/ SDIO interrupts Date: Tue, 15 Oct 2013 15:39:21 -0700 Message-Id: <1381876762-10892-2-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1381876762-10892-1-git-send-email-dianders@chromium.org> References: <1381876762-10892-1-git-send-email-dianders@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5385 Lines: 152 In the patch (9623b5b mmc: dw_mmc: Disable low power mode if SDIO interrupts are used) I added code that disabled the low power mode of dw_mmc when SDIO interrupts are used. That code worked but always felt a little hacky because we ended up disabling low power as a side effect of the first enable_sdio_irq() call. That wouldn't be so bad except that disabling low power involves a complicated process of writing to the CMD/CMDARG registers and that extra process makes it difficult to cleanly the read-modify-write race in dw_mci_enable_sdio_irq() (see future patch in the series). Change the code to take advantage of the init_card() callback of the mmc core to know when an SDIO card has been inserted. If we've got a SDIO card and we're configured to use SDIO Interrupts then turn off "low power mode" right away. Signed-off-by: Doug Anderson --- drivers/mmc/host/dw_mmc.c | 68 ++++++++++++++++++++++++----------------------- drivers/mmc/host/dw_mmc.h | 1 + 2 files changed, 36 insertions(+), 33 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 0a6a512..1b75816 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -822,7 +823,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) /* enable clock; only low power if no SDIO */ clk_en_a = SDMMC_CLKEN_ENABLE << slot->id; - if (!(mci_readl(host, INTMASK) & SDMMC_INT_SDIO(slot->id))) + if (!test_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags)) clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id; mci_writel(host, CLKENA, clk_en_a); @@ -1050,27 +1051,37 @@ static int dw_mci_get_cd(struct mmc_host *mmc) return present; } -/* - * Disable lower power mode. - * - * Low power mode will stop the card clock when idle. According to the - * description of the CLKENA register we should disable low power mode - * for SDIO cards if we need SDIO interrupts to work. - * - * This function is fast if low power mode is already disabled. - */ -static void dw_mci_disable_low_power(struct dw_mci_slot *slot) +static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card) { + struct dw_mci_slot *slot = mmc_priv(mmc); struct dw_mci *host = slot->host; - u32 clk_en_a; - const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id; - clk_en_a = mci_readl(host, CLKENA); + /* + * Low power mode will stop the card clock when idle. According to the + * description of the CLKENA register we should disable low power mode + * for SDIO cards if we need SDIO interrupts to work. + */ + if (mmc->caps | MMC_CAP_SDIO_IRQ) { + const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id; + u32 clk_en_a_old; + u32 clk_en_a; - if (clk_en_a & clken_low_pwr) { - mci_writel(host, CLKENA, clk_en_a & ~clken_low_pwr); - mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | - SDMMC_CMD_PRV_DAT_WAIT, 0); + clk_en_a_old = mci_readl(host, CLKENA); + + if (card->type == MMC_TYPE_SDIO || + card->type == MMC_TYPE_SD_COMBO) { + set_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags); + clk_en_a = clk_en_a_old & ~clken_low_pwr; + } else { + clear_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags); + clk_en_a = clk_en_a_old | clken_low_pwr; + } + + if (clk_en_a != clk_en_a_old) { + mci_writel(host, CLKENA, clk_en_a); + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | + SDMMC_CMD_PRV_DAT_WAIT, 0); + } } } @@ -1082,21 +1093,11 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb) /* Enable/disable Slot Specific SDIO interrupt */ int_mask = mci_readl(host, INTMASK); - if (enb) { - /* - * Turn off low power mode if it was enabled. This is a bit of - * a heavy operation and we disable / enable IRQs a lot, so - * we'll leave low power mode disabled and it will get - * re-enabled again in dw_mci_setup_bus(). - */ - dw_mci_disable_low_power(slot); - - mci_writel(host, INTMASK, - (int_mask | SDMMC_INT_SDIO(slot->id))); - } else { - mci_writel(host, INTMASK, - (int_mask & ~SDMMC_INT_SDIO(slot->id))); - } + if (enb) + int_mask |= SDMMC_INT_SDIO(slot->id); + else + int_mask &= ~SDMMC_INT_SDIO(slot->id); + mci_writel(host, INTMASK, int_mask); } static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode) @@ -1140,6 +1141,7 @@ static const struct mmc_host_ops dw_mci_ops = { .get_cd = dw_mci_get_cd, .enable_sdio_irq = dw_mci_enable_sdio_irq, .execute_tuning = dw_mci_execute_tuning, + .init_card = dw_mci_init_card, }; static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq) diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h index 6bf24ab..26d4657 100644 --- a/drivers/mmc/host/dw_mmc.h +++ b/drivers/mmc/host/dw_mmc.h @@ -227,6 +227,7 @@ struct dw_mci_slot { unsigned long flags; #define DW_MMC_CARD_PRESENT 0 #define DW_MMC_CARD_NEED_INIT 1 +#define DW_MMC_CARD_NO_LOW_PWR 2 int id; int last_detect_state; }; -- 1.8.4 -- 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/