[v4,1/7] mmc: cqhci: Provide helper for resetting both SDHCI and CQHCI

Commit Message

Brian Norris Oct. 26, 2022, 7:42 p.m. UTC

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: <[e-mail]>
Signed-off-by: Brian Norris <[e-mail]>
Acked-by: Adrian Hunter <[e-mail]>
---

Changes in v4:
 - Whitespace fixup
 - Add Adrian's Ack

Changes in v3:
 - New in v3 (replacing a simple 'cqe_private == NULL' patch in v2)

 drivers/mmc/host/sdhci-cqhci.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 drivers/mmc/host/sdhci-cqhci.h

Comments

Florian Fainelli Oct. 26, 2022, 7:44 p.m. UTC | #1

On 10/26/22 12:42, 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: <[e-mail]>
> Signed-off-by: Brian Norris <[e-mail]>
> Acked-by: Adrian Hunter <[e-mail]>

Reviewed-by: Florian Fainelli <[e-mail]>

Patch

diff --git a/drivers/mmc/host/sdhci-cqhci.h b/drivers/mmc/host/sdhci-cqhci.h
new file mode 100644
index 000000000000..cf8e7ba71bbd
--- /dev/null
+++ b/drivers/mmc/host/sdhci-cqhci.h
@@ -0,0 +1,24 @@ 
+/* 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);
+}
+
+#endif /* __MMC_HOST_SDHCI_CQHCI_H__ */