Re: [PATCH 1/3] dt-bindings: mmc: Add DTS property to disable DCMDs on Arasan controllers
From: Christoph MÃllner
Date: Fri Mar 01 2019 - 13:20:22 EST
> On 01.03.2019, at 19:17, Heiko Stuebner <heiko@xxxxxxxxx> wrote:
> Am Freitag, 1. MÃrz 2019, 17:43:45 CET schrieb Christoph Muellner:
>> Direct commands (DCMDs) are an optional feature of eMMC 5.1's command
>> queue engine (CQE). The Arasan eMMC 5.1 controller uses the CQHCI,
>> which exposes a control register bit to enable the feature.
>> The current implementation sets this bit unconditionally.
>> This patch allows to surpress the feature activation,
>> by specifying the property disable-cqe-dcmd.
>> Signed-off-by: Christoph Muellner <christoph.muellner@xxxxxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Philipp Tomsich <philipp.tomsich@xxxxxxxxxxxxxxxxxxxxx>
> Patch subject is needs improvement :-) .
> I did scratch my head a lot regarding "where is the code change"
> until I actually looked into the patch itself, so you probably want
> mmc: sdhci-of-arasan: Add DTS property to disable DCMDs
> or similar instead of "dt-bindings: ..." here to match the subsystem.
Yes, I've spotted this as well after sending it.
I've already renamed to "mmc: sdhci-of-arasan: Add DTS property to disable DCMDs." for v2.
>> drivers/mmc/host/sdhci-of-arasan.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>> index c9e3e050ccc8..88dc3f00a5be 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -832,7 +832,10 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>> host->mmc_host_ops.start_signal_voltage_switch =
>> sdhci_arasan->has_cqe = true;
>> - host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
>> + host->mmc->caps2 |= MMC_CAP2_CQE;
>> + if (!of_property_read_bool(np, "disable-cqe-dcmd"))
>> + host->mmc->caps2 |= MMC_CAP2_CQE_DCMD;
>> ret = sdhci_arasan_add_host(sdhci_arasan);