From: Ulf Hansson <ulf.hansson@linaro.org>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
DTML <devicetree@vger.kernel.org>,
jianxin.pan@amlogic.com,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>,
"open list:ARM/Amlogic Meson..."
<linux-amlogic@lists.infradead.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH RFC v1 2/2] mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host
Date: Thu, 22 Aug 2019 15:52:24 +0200 [thread overview]
Message-ID: <CAPDyKFoFQ_QvHD-+Mg_VAR5rqs3CM_h7dw25p81JTzE1Yz7d1A@mail.gmail.com> (raw)
In-Reply-To: <20190708173330.13217-3-martin.blumenstingl@googlemail.com>
On Mon, 8 Jul 2019 at 19:33, Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> WiP - only partially working - see performance numbers.
>
> Odroid-C1 eMMC (HS-200):
> Amlogic's vendor driver @ Linux 3.10:
> 7781351936 bytes (7.8 GB) copied, 134.714 s, 57.8 MB/s
> This driver:
> 7781351936 bytes (7.8 GB, 7.2 GiB) copied, 189.02 s, 41.2 MB/s
>
> EC-100 eMMC (HS MMC):
> Amlogic's vendor driver @ Linux 3.10:
> 15762194432 bytes (16 GB) copied, 422.967 s, 37.3 MB/s
> This driver:
> 15762194432 bytes (16 GB, 15 GiB) copied, 9232.65 s, 1.7 MB/s
>
> 1) Amlogic's vendor driver does some magic with the divider:
> clk_div = input_rate / clk_ios - !(input_rate%clk_ios);
> if (!(clk_div & 0x01)) // if even number, turn it to an odd one
> clk_div++;
> It's not clear to me whether what the reason behind this is, what is
> supposed to be achieved with this?
>
> 2) The hardcoded RX clock phases are taken from the vendor driver. It
> seems that these are only valid when fclk_div3 is used as input
> clock (however, there are four more inputs). It's not clear to me how
> to calculate the RX clock phases in set_ios based on the input clock
> and the ios rate.
>
> 3) The hardware supports a timeout IRQ but the max_busy_timeout is not
> documented anywhere.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Martin, overall this looks good to me. Once you moved from RFC to a
formal patch I will check again, of course.
There are a couple of calls to readl_poll_timeout(), for different
reasons, that I have some questions about, but we can discuss those in
the next step.
[...]
Kind regards
Uffe
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next prev parent reply other threads:[~2019-08-22 13:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-08 17:33 [PATCH RFC v1 0/2] Amlogic 32-bit Meson SDHC MMC controller driver Martin Blumenstingl
2019-07-08 17:33 ` [PATCH RFC v1 1/2] dt-bindings: mmc: Document the Amlogic Meson SDHC MMC host controller Martin Blumenstingl
2019-07-24 20:04 ` Rob Herring
2019-07-08 17:33 ` [PATCH RFC v1 2/2] mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host Martin Blumenstingl
2019-07-08 17:40 ` Martin Blumenstingl
2019-08-22 13:52 ` Ulf Hansson [this message]
2019-08-24 21:34 ` Martin Blumenstingl
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