Commit 4228b213 authored Apr 20, 2016 by Adrian Hunter Committed by Ulf Hansson May 02, 2016

mmc: sdhci: Remove SDHCI_SDR104_NEEDS_TUNING



SDHCI_SDR104_NEEDS_TUNING was originally named SDHCI_HS200_NEEDS_TUNING
and was added in commit 069c9f14 ("mmc: host: Adds support for eMMC
4.5 HS200 mode").

That commit conflated SDHCI_SDR50_NEEDS_TUNING and SDHCI_HS200_NEEDS_TUNING
due to what appears to be misplaced parentheses.

Commit 156e14b1 ("mmc: sdhci: fix caps2 for HS200") made HS200
configuration equivalent to SDR104 configuration, renaming
SDHCI_HS200_NEEDS_TUNING to SDHCI_SDR104_NEEDS_TUNING despite tuning for
HS200 now being non-optional.

The mix-up with SDHCI_SDR50_NEEDS_TUNING remained and became more obvious
after commit 4b6f37d3 ("mmc: sdhci: clean up sdhci_execute_tuning()
decision") where the author noted the patch was "reflecting what the
original code was doing, it shows that it may not be what the author
actually intended."

The way the code is currently written, SDHCI_SDR104_NEEDS_TUNING
causes tuning to be done always for SDR50 mode if SDR104 mode is
also supported by the host controller.  That makes no sense because
we already have capabilities bit SDHCI_USE_SDR50_TUNING and
corresponding flag SDHCI_SDR50_NEEDS_TUNING for that purpose.

Given the dubious origins of SDHCI_SDR104_NEEDS_TUNING, it seems
reasonable to remove it.  The benefit being SDR50 mode will now not
un-nessessarily do tuning.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

parent 5c59065b

drivers/mmc/host/sdhci.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -1906,8 +1906,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
		break;

		case MMC_TIMING_UHS_SDR50:
		if (host->flags & SDHCI_SDR50_NEEDS_TUNING \|\|
		host->flags & SDHCI_SDR104_NEEDS_TUNING)
		if (host->flags & SDHCI_SDR50_NEEDS_TUNING)
		break;
		/* FALLTHROUGH */

		@@ -3171,10 +3170,6 @@ int sdhci_add_host(struct sdhci_host *host)
		if (caps[1] & SDHCI_USE_SDR50_TUNING)
		host->flags \|= SDHCI_SDR50_NEEDS_TUNING;

		/* Does the host need tuning for SDR104 / HS200? */
		if (mmc->caps2 & MMC_CAP2_HS200)
		host->flags \|= SDHCI_SDR104_NEEDS_TUNING;

		/* Driver Type(s) (A, C, D) supported by the host */
		if (caps[1] & SDHCI_DRIVER_TYPE_A)
		mmc->caps \|= MMC_CAP_DRIVER_TYPE_A;

drivers/mmc/host/sdhci.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -445,7 +445,6 @@ struct sdhci_host {
		#define SDHCI_AUTO_CMD23 (1<<7) /* Auto CMD23 support */
		#define SDHCI_PV_ENABLED (1<<8) /* Preset value enabled */
		#define SDHCI_SDIO_IRQ_ENABLED (1<<9) /* SDIO irq enabled */
		#define SDHCI_SDR104_NEEDS_TUNING (1<<10) /* SDR104/HS200 needs tuning */
		#define SDHCI_USE_64_BIT_DMA (1<<12) /* Use 64-bit DMA */
		#define SDHCI_HS400_TUNING (1<<13) /* Tuning for HS400 */

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