From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753330AbdHOHd7 (ORCPT ); Tue, 15 Aug 2017 03:33:59 -0400 Received: from mga05.intel.com ([192.55.52.43]:2148 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753185AbdHOHd5 (ORCPT ); Tue, 15 Aug 2017 03:33:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,376,1498546800"; d="scan'208";a="890039038" Subject: Re: [RFC PATCH 1/7] mmc: sdhci: Add quirk to indicate no CRC stripping in MMC_RSP_136 To: Kishon Vijay Abraham I , Ulf Hansson , Tony Lindgren , Rob Herring Cc: nsekhar@ti.com, linux-omap@vger.kernel.org, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <20170807160142.12134-1-kishon@ti.com> <20170807160142.12134-2-kishon@ti.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <872c7194-3d48-47e5-6396-7189bf841a42@intel.com> Date: Tue, 15 Aug 2017 10:27:30 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170807160142.12134-2-kishon@ti.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/08/17 19:01, Kishon Vijay Abraham I wrote: > TI's implementation of sdhci controller used in DRA7 SoC's doesn't > strip CRC in responses with length 136 bits. Add quirk to indicate > the controller does not strip CRC in MMC_RSP_136. If this quirk is > set sdhci library shouldn't shift the response present in > SDHCI_RESPONSE register. > > Signed-off-by: Kishon Vijay Abraham I > --- > drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++-------- > drivers/mmc/host/sdhci.h | 2 ++ > 2 files changed, 21 insertions(+), 8 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index ecd0d4350e8a..ece3751d2a25 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -1182,14 +1182,25 @@ static void sdhci_finish_command(struct sdhci_host *host) > > if (cmd->flags & MMC_RSP_PRESENT) { > if (cmd->flags & MMC_RSP_136) { > - /* CRC is stripped so we need to do some shifting. */ > - for (i = 0;i < 4;i++) { > - cmd->resp[i] = sdhci_readl(host, > - SDHCI_RESPONSE + (3-i)*4) << 8; > - if (i != 3) > - cmd->resp[i] |= > - sdhci_readb(host, > - SDHCI_RESPONSE + (3-i)*4-1); > + if (!(host->quirks2 & SDHCI_QUIRK2_NO_CRC_STRIPPING)) { This is about the 136-bit response so let's put that in the quirk name. How about SDHCI_QUIRK2_RSP_136_HAS_CRC > + /* > + * CRC is stripped so we need to do some > + * shifting. > + */ > + for (i = 0; i < 4; i++) { > + cmd->resp[i] = > + sdhci_readl(host, SDHCI_RESPONSE > + + (3 - i) * 4) << 8; > + if (i != 3) > + cmd->resp[i] |= > + sdhci_readb(host, SDHCI_RESPONSE > + + (3 - i) * 4 - 1); > + } > + } else { > + for (i = 0; i < 4; i++) > + cmd->resp[i] = > + sdhci_readl(host, SDHCI_RESPONSE + > + (3 - i) * 4); > } This is all very jammed up against the 80 column margin. Please make a new patch to separate it into a new function sdhci_read_rsp_136() and then another patch to add the quirk. i.e. completely untested! From: Adrian Hunter Date: Tue, 15 Aug 2017 10:22:09 +0300 Subject: [PATCH] mmc: sdhci: Tidy reading 136-bit responses Read each register only once and move the code to a separate function so that it is not jammed against the 80 column margin. Signed-off-by: Adrian Hunter --- drivers/mmc/host/sdhci.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 32a0e8f6fb04..21d0b36d642f 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1173,6 +1173,23 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) } EXPORT_SYMBOL_GPL(sdhci_send_command); +static void sdhci_read_rsp_136(struct sdhci_host *host, struct mmc_command *cmd) +{ + int i, reg; + + for (i = 0; i < 4; i++) { + reg = SDHCI_RESPONSE + (3 - i) * 4; + cmd->resp[i] = sdhci_readl(host, reg); + } + + /* CRC is stripped so we need to do some shifting */ + for (i = 0; i < 4; i++) { + cmd->resp[i] =<< 8; + if (i != 3) + cmd->resp[i] |= cmd->resp[i + 1] >> 24; + } +} + static void sdhci_finish_command(struct sdhci_host *host) { struct mmc_command *cmd = host->cmd; @@ -1182,15 +1199,7 @@ static void sdhci_finish_command(struct sdhci_host *host) if (cmd->flags & MMC_RSP_PRESENT) { if (cmd->flags & MMC_RSP_136) { - /* CRC is stripped so we need to do some shifting. */ - for (i = 0;i < 4;i++) { - cmd->resp[i] = sdhci_readl(host, - SDHCI_RESPONSE + (3-i)*4) << 8; - if (i != 3) - cmd->resp[i] |= - sdhci_readb(host, - SDHCI_RESPONSE + (3-i)*4-1); - } + sdhci_read_rsp_136(host, cmd); } else { cmd->resp[0] = sdhci_readl(host, SDHCI_RESPONSE); } -- 1.9.1 > } else { > cmd->resp[0] = sdhci_readl(host, SDHCI_RESPONSE); > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h > index 0469fa191493..6905131f603d 100644 > --- a/drivers/mmc/host/sdhci.h > +++ b/drivers/mmc/host/sdhci.h > @@ -435,6 +435,8 @@ struct sdhci_host { > #define SDHCI_QUIRK2_ACMD23_BROKEN (1<<14) > /* Broken Clock divider zero in controller */ > #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN (1<<15) > +/* Controller does not have CRC stripped in Command Response */ > +#define SDHCI_QUIRK2_NO_CRC_STRIPPING (1<<16) > > int irq; /* Device IRQ */ > void __iomem *ioaddr; /* Mapped address */ >