From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753161AbeCPOWF (ORCPT ); Fri, 16 Mar 2018 10:22:05 -0400 Received: from mga09.intel.com ([134.134.136.24]:65421 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753140AbeCPOWB (ORCPT ); Fri, 16 Mar 2018 10:22:01 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,316,1517904000"; d="scan'208";a="28539971" Subject: Re: [PATCH v3 07/11] mmc: sdhci: Program a relatively accurate SW timeout value To: Kishon Vijay Abraham I , Ulf Hansson , Tony Lindgren Cc: Rob Herring , Mark Rutland , Russell King , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20180307132020.30951-1-kishon@ti.com> <20180307132020.30951-8-kishon@ti.com> <1e87e5f9-13e1-765b-f077-26a55359b2c3@intel.com> <47752066-aeda-87bc-6928-1a9b80f1c45c@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: <49210daa-b593-4b34-abf5-be81580723bc@intel.com> Date: Fri, 16 Mar 2018 16:21:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <47752066-aeda-87bc-6928-1a9b80f1c45c@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 16/03/18 08:29, Kishon Vijay Abraham I wrote: > Hi, > > On Thursday 15 March 2018 06:43 PM, Adrian Hunter wrote: >> On 07/03/18 15:20, Kishon Vijay Abraham I wrote: >>> sdhci has a 10 second timeout to catch devices that stop responding. >>> Instead of programming 10 second arbitrary value, calculate the total time >>> it would take for the entire transfer to happen and program the timeout >>> value accordingly. >>> >>> Signed-off-by: Kishon Vijay Abraham I >>> --- >>> drivers/mmc/host/sdhci.c | 47 ++++++++++++++++++++++++++++++++++++++++------- >>> drivers/mmc/host/sdhci.h | 10 ++++++++++ >>> 2 files changed, 50 insertions(+), 7 deletions(-) >>> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >>> index 1dd117cbeb6e..baab67bfa39b 100644 >>> --- a/drivers/mmc/host/sdhci.c >>> +++ b/drivers/mmc/host/sdhci.c >>> @@ -709,6 +709,36 @@ static u32 sdhci_sdma_address(struct sdhci_host *host) >>> return sg_dma_address(host->data->sg); >>> } >>> >>> +static void sdhci_calc_sw_timeout(struct sdhci_host *host, >>> + struct mmc_command *cmd, >>> + unsigned int target_timeout) >>> +{ >>> + struct mmc_data *data = cmd->data; >>> + struct mmc_host *mmc = host->mmc; >>> + u64 transfer_time; >>> + struct mmc_ios *ios = &mmc->ios; >>> + unsigned char bus_width = 1 << ios->bus_width; >>> + unsigned int blksz; >>> + unsigned int freq; >>> + >>> + if (data) { >>> + blksz = data->blksz; >>> + freq = host->mmc->actual_clock ? : host->clock; >>> + transfer_time = (u64)blksz * NSEC_PER_SEC * (8 / bus_width); >>> + do_div(transfer_time, freq); >>> + /* multiply by '2' to account for any unknowns */ >>> + transfer_time = transfer_time * 2; >>> + /* calculate timeout for the entire data */ >>> + host->data_timeout = (data->blocks * ((target_timeout * >>> + NSEC_PER_USEC) + >>> + transfer_time)); >> >> (target_timeout * NSEC_PER_USEC) might be 32-bit and therefore overflow >> for timeouts greater than about 4 seconds. >> >>> + } else { >>> + host->data_timeout = (u64)target_timeout * NSEC_PER_USEC; >>> + } >>> + >>> + host->data_timeout += MMC_CMD_TRANSFER_TIME; >> >> Need to allow for target_timeout == 0 so: >> >> if (host->data_timeout) >> host->data_timeout += MMC_CMD_TRANSFER_TIME; >> >>> +} >>> + >>> static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd) >>> { >>> u8 count; >>> @@ -766,6 +796,7 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd) >>> if (count >= 0xF) >>> break; >>> } >>> + sdhci_calc_sw_timeout(host, cmd, target_timeout); >> >> If you make the changes I suggest for patch 6, then this would >> move sdhci_calc_sw_timeout() into sdhci_set_timeout(). >> >> I suggest you factor out the target_timeout calculation e.g. >> >> static unsigned int sdhci_target_timeout(struct sdhci_host *host, >> struct mmc_command *cmd, >> struct mmc_data *data) >> { >> unsigned int target_timeout; >> >> /* timeout in us */ >> if (!data) >> target_timeout = cmd->busy_timeout * 1000; >> else { >> target_timeout = DIV_ROUND_UP(data->timeout_ns, 1000); >> if (host->clock && data->timeout_clks) { >> unsigned long long val; >> >> /* >> * data->timeout_clks is in units of clock cycles. >> * host->clock is in Hz. target_timeout is in us. >> * Hence, us = 1000000 * cycles / Hz. Round up. >> */ >> val = 1000000ULL * data->timeout_clks; >> if (do_div(val, host->clock)) >> target_timeout++; >> target_timeout += val; >> } >> } >> >> return target_timeout; >> } >> >> And call it from sdhci_calc_sw_timeout() >> >>> >>> return count; >>> } >>> @@ -1175,13 +1206,6 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) >>> mdelay(1); >>> } >>> >>> - timeout = jiffies; >>> - if (!cmd->data && cmd->busy_timeout > 9000) >>> - timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ; >>> - else >>> - timeout += 10 * HZ; >>> - sdhci_mod_timer(host, cmd->mrq, timeout); >>> - >>> host->cmd = cmd; >>> if (sdhci_data_line_cmd(cmd)) { >>> WARN_ON(host->data_cmd); >>> @@ -1221,6 +1245,15 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) >>> cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200) >>> flags |= SDHCI_CMD_DATA; >>> >>> + timeout = jiffies; >>> + if (host->data_timeout > 0) { >> >> This can be just: >> >> if (host->data_timeout) { >> >>> + timeout += nsecs_to_jiffies(host->data_timeout); >>> + host->data_timeout = 0; >> >> It would be better to initialize host->data_timeout = 0 at the top of >> sdhci_prepare_data(). >> >> Also still need: >> >> else if (!cmd->data && cmd->busy_timeout > 9000) { >> timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ; > > sdhci_calc_sw_timeout should have calculated the timeout for this case too no? Yes, but I was thinking you would only calculate when it was needed.