From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752569AbbJWMHn (ORCPT ); Fri, 23 Oct 2015 08:07:43 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:57880 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbbJWMHl (ORCPT ); Fri, 23 Oct 2015 08:07:41 -0400 X-AuditID: cbfee68f-f796f6d0000014a4-a5-562a230a5726 Message-id: <562A230A.80409@samsung.com> Date: Fri, 23 Oct 2015 21:07:38 +0900 From: Jaehoon Chung User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-version: 1.0 To: Shawn Lin Cc: Ulf Hansson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] mmc: dw_mmc: add hw_reset support References: <1445494740-16778-1-git-send-email-shawn.lin@rock-chips.com> <1445494785-16864-1-git-send-email-shawn.lin@rock-chips.com> In-reply-to: <1445494785-16864-1-git-send-email-shawn.lin@rock-chips.com> Content-type: text/plain; charset=utf-8 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupkkeLIzCtJLcpLzFFi42JZI2JSrMulrBVmcKZT1eLyrjlsFkf+9zNa 3HmyntXi+NpwBxaPO9f2sHn8nbWfxePzJrkA5igum5TUnMyy1CJ9uwSujKmbjrEX7JeqmNfQ wN7A2CXaxcjJISFgIvHv/082CFtM4sK99UA2F4eQwApGiQfPXjHBFO07/IgRIrGUUWL933Us EM4DRom223/B2nkFNCROTO5iBLFZBFQlWqb+AIuzCehIbP92HGySqECYxIN1e1kh6gUlfky+ xwJiiwD13jh7HayeWSBZouPfUbC4sICVxLs/J1ghlrUzShyc+BWsiFPAU2LX3l72LkYOoAZ1 iSlTciF65SU2r3nLDFIvIbCKXaJp+h+ogwQkvk0+xAJSLyEgK7HpADPEZ5ISB1fcYJnAKDYL yUmzEKbOQjJ1ASPzKkbR1ILkguKk9CJjveLE3OLSvHS95PzcTYzAGDr971n/Dsa7B6wPMQpw MCrx8L7o0AwTYk0sK67MPcRoCnTERGYp0eR8YKTmlcQbGpsZWZiamBobmVuaKYnzLpT6GSwk kJ5YkpqdmlqQWhRfVJqTWnyIkYmDU6qBUf92slktx7yd054bLGz7EWuerc//86xn6tfE7mN2 /7KjWi/vv/t/eyrD7bCS1f+UHhUdNd954rOSxRU2X90JD9p+t+T+qO2KSg56J/yK8btFSYfa CqnTT3zd2ne2avYmV/x7Z+y9x2bmddcvxYs3LJbo+eDvHiK0oUXsg46hS0p9fO7Daq8sJZbi jERDLeai4kQAgqbohpwCAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrGIsWRmVeSWpSXmKPExsVy+t9jAV0uZa0wgw+35S0u75rDZnHkfz+j xZ0n61ktjq8Nd2DxuHNtD5vH31n7WTw+b5ILYI5qYLTJSE1MSS1SSM1Lzk/JzEu3VfIOjneO NzUzMNQ1tLQwV1LIS8xNtVVy8QnQdcvMAdqmpFCWmFMKFApILC5W0rfDNCE0xE3XAqYxQtc3 JAiux8gADSSsYcyYuukYe8F+qYp5DQ3sDYxdol2MnBwSAiYS+w4/YoSwxSQu3FvP1sXIxSEk sJRRYv3fdSwQzgNGibbbf9lAqngFNCROTO4C62ARUJVomfoDLM4moCOx/dtxJhBbVCBM4sG6 vawQ9YISPybfYwGxRYB6b5y9DlbPLJAs0fHvKFhcWMBK4t2fE6wQy9oZJQ5O/ApWxCngKbFr by97FyMHUIO6xJQpuRC98hKb17xlnsAoMAvJilkIVbOQVC1gZF7FKJFakFxQnJSea5iXWq5X nJhbXJqXrpecn7uJERynz6R2MB7c5X6IUYCDUYmH90WHZpgQa2JZcWXuIUYJDmYlEd5SIa0w Id6UxMqq1KL8+KLSnNTiQ4ymwDCYyCwlmpwPTCF5JfGGxiZmRpZG5oYWRsbmSuK8FzI0woQE 0hNLUrNTUwtSi2D6mDg4pRoYGWdPNLyzIfd62PHz/pqXDugoZseu09d3tblc25jcEJ0aO6dy 2zFl6zvn5Lf9+Re4eL2wta7Re3uhAL3sCO41O/qYVv6O9prDr9rYb+Qtf/PteteYhmT5rBXL d60Odkg7zOrVMb3S2yxz1nPeM3s00hOPPtsV9WbO+c0vDdbar5gyd9vGNaJnlFiKMxINtZiL ihMB/ViWBukCAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Shawn. On 10/22/2015 03:19 PM, Shawn Lin wrote: > This patch implement hw_reset function for DesignWare > MMC controller. By adding this feature, mmc blk can > do some basic recovery if emmc device cannot work any > more for unknown reasons. Are there any other issue before applied this patch? > > Signed-off-by: Shawn Lin > > --- > > drivers/mmc/host/dw_mmc.c | 29 +++++++++++++++++++++++++++++ > drivers/mmc/host/dw_mmc.h | 4 ++++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 6e600e8..8a0f2995 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1478,6 +1478,34 @@ static int dw_mci_get_cd(struct mmc_host *mmc) > return present; > } > > +static void dw_mci_hw_reset(struct mmc_host *mmc) > +{ > + struct dw_mci_slot *slot = mmc_priv(mmc); > + struct dw_mci *host = slot->host; > + > + if (host->use_dma == TRANS_MODE_IDMAC) > + dw_mci_idmac_reset(host); > + > + if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET) || > + (!dw_mci_ctrl_reset(host, SDMMC_CTRL_FIFO_RESET))) Why does it reset twice? Can't reset together with DMA and FIFO? dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET | SDMMC_CTRL_FIFO_RESET)? > + return; > + > + /* CARD_RESET > + * According to eMMC spec > + * tRstW >= 1us: RST_n pulse width > + * tRSCA >= 200us: RST_n to Command time > + * tRSTH >= 1us: RST_n high period > + * Note: add some margin to make rst timing not too > + * "spec" for some bad qulity eMMC devices. some bad quality? Which devices are bad quality devices? > + */ > + mci_writel(slot->host, RST_N, SDMMC_RST_HWRESET); > + wmb(); /* drain writebuffer */ > + usleep_range(5, 10); > + mci_writel(slot->host, RST_N, SDMMC_RST_HWACTIVE); > + wmb(); /* drain writebuffer */ > + usleep_range(500, 1000); Need to drain writebuffer at here? I don't know why you choose those values..Just some margin? And if you want to apply this, i recommend to use the shift with card number. Best Regards, Jaehoon Chung > +} > + > static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card) > { > struct dw_mci_slot *slot = mmc_priv(mmc); > @@ -1564,6 +1592,7 @@ static const struct mmc_host_ops dw_mci_ops = { > .set_ios = dw_mci_set_ios, > .get_ro = dw_mci_get_ro, > .get_cd = dw_mci_get_cd, > + .hw_reset = dw_mci_hw_reset, > .enable_sdio_irq = dw_mci_enable_sdio_irq, > .execute_tuning = dw_mci_execute_tuning, > .card_busy = dw_mci_card_busy, > diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h > index f2a88d4..9df18c1 100644 > --- a/drivers/mmc/host/dw_mmc.h > +++ b/drivers/mmc/host/dw_mmc.h > @@ -46,6 +46,7 @@ > #define SDMMC_VERID 0x06c > #define SDMMC_HCON 0x070 > #define SDMMC_UHS_REG 0x074 > +#define SDMMC_RST_N 0x078 > #define SDMMC_BMOD 0x080 > #define SDMMC_PLDMND 0x084 > #define SDMMC_DBADDR 0x088 > @@ -169,6 +170,9 @@ > #define SDMMC_IDMAC_ENABLE BIT(7) > #define SDMMC_IDMAC_FB BIT(1) > #define SDMMC_IDMAC_SWRESET BIT(0) > +/* H/W reset*/ > +#define SDMMC_RST_HWACTIVE 0x1 > +#define SDMMC_RST_HWRESET 0x0 > /* Version ID register define */ > #define SDMMC_GET_VERID(x) ((x) & 0xFFFF) > /* Card read threshold */ >