From: Trent Piepho <tpiepho@impinj.com>
To: "yibin.gong@nxp.com" <yibin.gong@nxp.com>,
"u.kleine-koenig@pengutronix.de" <u.kleine-koenig@pengutronix.de>,
"broonie@kernel.org" <broonie@kernel.org>
Cc: "marex@denx.de" <marex@denx.de>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
"linux-imx@nxp.com" <linux-imx@nxp.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-spi@vger.kernel.org" <linux-spi@vger.kernel.org>
Subject: Re: [PATCH v3 5/5] spi: imx: drop useless member speed_hz from driver data struct
Date: Fri, 30 Nov 2018 17:21:40 +0000 [thread overview]
Message-ID: <1543598496.18519.101.camel@impinj.com> (raw)
In-Reply-To: <20181130064709.6998-6-u.kleine-koenig@pengutronix.de>
On Fri, 2018-11-30 at 07:47 +0100, Uwe Kleine-König wrote:
> The driver data's member variable just caches the transfer's speed_hz
> member. All users of the former now have access directly to the latter.
> So fix them to use the uncached value and remove the cache.
What should have been done with this is to compare the next transfer's
speed_hz to this cached value, and not preprogram the clock if it has
not changed. Since usually it doesn't change between transfers.
spi_bus_clk caches the actual spi bus clock, which is often not exactly
the same as the transfer speed, so using it compare against the next
transfer doesn't work as well.
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next prev parent reply other threads:[~2018-11-30 17:21 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-30 6:47 [PATCH v3 0/5] spi: imx: Fix polarity switching for mx51-ecspi Uwe Kleine-König
2018-11-30 6:47 ` [PATCH v3 1/5] spi: imx: add a device specific prepare_message callback Uwe Kleine-König
2018-11-30 6:47 ` [PATCH v3 2/5] spi: imx: mx51-ecspi: Move some initialisation to prepare_message hook Uwe Kleine-König
2018-12-03 8:00 ` Robin Gong
2018-12-03 8:18 ` Uwe Kleine-König
2018-11-30 6:47 ` [PATCH v3 3/5] spi: imx: style fixes Uwe Kleine-König
2018-11-30 6:47 ` [PATCH v3 4/5] spi: imx: rename config callback and add useful parameters Uwe Kleine-König
2018-12-03 8:09 ` Robin Gong
2018-12-03 8:29 ` Uwe Kleine-König
2018-11-30 6:47 ` [PATCH v3 5/5] spi: imx: drop useless member speed_hz from driver data struct Uwe Kleine-König
2018-11-30 17:21 ` Trent Piepho [this message]
2018-11-30 17:50 ` Uwe Kleine-König
2018-11-30 18:10 ` Trent Piepho
2018-11-30 18:21 ` Uwe Kleine-König
2018-12-10 21:52 ` [PATCH v3 0/5] spi: imx: Fix polarity switching for mx51-ecspi Uwe Kleine-König
2018-12-11 1:14 ` Mark Brown
2018-12-11 7:13 ` Uwe Kleine-König
2018-12-11 11:56 ` Mark Brown
2018-12-11 20:11 ` Uwe Kleine-König
2018-12-11 20:40 ` Mark Brown
2018-12-12 9:21 ` Mark Brown
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