Re: [PATCH v3 1/7] mmc: cqhci: Provide helper for resetting both SDHCI and CQHCI

From: Adrian Hunter <adrian.hunter@intel.com>
To: Brian Norris <briannorris@chromium.org>,
	Ulf Hansson <ulf.hansson@linaro.org>
Cc: Shawn Lin <shawn.lin@rock-chips.com>,
	linux-mmc@vger.kernel.org, Al Cooper <alcooperx@gmail.com>,
	Bjorn Andersson <andersson@kernel.org>,
	Sowjanya Komatineni <skomatineni@nvidia.com>,
	Broadcom internal kernel review list 
	<bcm-kernel-feedback-list@broadcom.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Konrad Dybcio <konrad.dybcio@somainline.org>,
	Florian Fainelli <f.fainelli@gmail.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Fabio Estevam <festevam@gmail.com>,
	Michal Simek <michal.simek@xilinx.com>,
	linux-kernel@vger.kernel.org, Shawn Guo <shawnguo@kernel.org>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	linux-arm-msm@vger.kernel.org, Haibo Chen <haibo.chen@nxp.com>,
	Andy Gross <agross@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	Faiz Abbas <faiz_abbas@ti.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH v3 1/7] mmc: cqhci: Provide helper for resetting both SDHCI and CQHCI
Date: Tue, 25 Oct 2022 16:09:06 +0300	[thread overview]
Message-ID: <de5186fb-e176-23df-63fc-2a436e765c14@intel.com> (raw)
In-Reply-To: <20221024105229.v3.1.Ie85faa09432bfe1b0890d8c24ff95e17f3097317@changeid>

On 24/10/22 20:54, Brian Norris wrote:
> Several SDHCI drivers need to deactivate command queueing in their reset
> hook (see sdhci_cqhci_reset() / sdhci-pci-core.c, for example), and
> several more are coming.
> 
> Those reset implementations have some small subtleties (e.g., ordering
> of initialization of SDHCI vs. CQHCI might leave us resetting with a
> NULL ->cqe_private), and are often identical across different host
> drivers.
> 
> We also don't want to force a dependency between SDHCI and CQHCI, or
> vice versa; non-SDHCI drivers use CQHCI, and SDHCI drivers might support
> command queueing through some other means.
> 
> So, implement a small helper, to avoid repeating the same mistakes in
> different drivers. Simply stick it in a header, because it's so small it
> doesn't deserve its own module right now, and inlining to each driver is
> pretty reasonable.
> 
> This is marked for -stable, as it is an important prerequisite patch for
> several SDHCI controller bugfixes that follow.
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>

One cosmetic nit, otherwise:

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> 
> Changes in v3:
>  - New in v3 (replacing a simple 'cqe_private == NULL' patch in v2)
> 
>  drivers/mmc/host/sdhci-cqhci.h | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>  create mode 100644 drivers/mmc/host/sdhci-cqhci.h
> 
> diff --git a/drivers/mmc/host/sdhci-cqhci.h b/drivers/mmc/host/sdhci-cqhci.h
> new file mode 100644
> index 000000000000..270ab1f1de3c
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-cqhci.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright 2022 The Chromium OS Authors
> + *
> + * Support that applies to the combination of SDHCI and CQHCI, while not
> + * expressing a dependency between the two modules.
> + */
> +
> +#ifndef __MMC_HOST_SDHCI_CQHCI_H__
> +#define __MMC_HOST_SDHCI_CQHCI_H__
> +
> +#include "cqhci.h"
> +#include "sdhci.h"
> +
> +static inline void sdhci_and_cqhci_reset(struct sdhci_host *host, u8 mask)
> +{
> +	if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask & SDHCI_RESET_ALL) &&
> +	    host->mmc->cqe_private)
> +		cqhci_deactivate(host->mmc);
> +
> +	sdhci_reset(host, mask);
> +}
> +
> +

Double blank line

> +#endif /* __MMC_HOST_SDHCI_CQHCI_H__ */