From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Schmelzer Date: Wed, 24 Aug 2016 12:51:05 +0200 Subject: [U-Boot] [PATCH v1] cmd/sf: probe flash with speed of last known flash or speed from devicetree In-Reply-To: <86295f5e-70ad-e660-4ff4-2046e12a6780@ti.com> References: <1472033154-31475-1-git-send-email-oe5hpm@oevsv.at> <86295f5e-70ad-e660-4ff4-2046e12a6780@ti.com> Message-ID: <57BD7C19.4030401@schmelzer.or.at> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 08/24/2016 12:35 PM, Vignesh R wrote: > Hi, Hi Vignesh, > On Wednesday 24 August 2016 03:35 PM, Hannes Schmelzer wrote: >> During probing flashes on the spi bus using the "sf probe" command, a >> maybe existing flash (from fdt) is unbound and removed to force the >> 'spi_flash_probe_bus_cs' really scanning the bus. >> >> Today the bus is probed with speed 0, this triggers several fall-back >> mechanism (mostly in the low-level drivers) to catch the impossible zero >> speed. >> Result of this is, that the spi-flash runs at very low speed depending >> on the minimum given by low-level driver/hardware. >> >> Values like 'spi-max-frequency' from devicetree are ignored totally >> today. >> >> This commit changes as following: >> - if there was already some flash binding in devicetree (having some >> spi-max-frequency within) speed is taken from it >> - if no flash binding was present for speed the 'spi-max-frequency' from >> the responsible spi node is taken. >> >> Signed-off-by: Hannes Schmelzer > > With commit 96907c0fe50a8 ("dm: spi: Read default speed and mode values > from DT") sf probe picks spi-max-frequency from DT if not specified as > argument. > > But when sf probe is called second time, the command fails to pick up > speed from DT. This is because flash node is unbound from the SPI > controller children nodes. Below patch should fix this issue: > https://patchwork.ozlabs.org/patch/659979/ sry ... i didn't took notice about this patch at the beginning of mine. Just reviewed and tested it. The named patch makes things a bit better but not good. Speed for flash still has no relationship to 'spi-max-frequency' from the spi-bus nor with a maybe defined flash in dts. Rather the #define CONFIG_ENV_SPI_MAX_HZ is used. But for my thinking the way we should walk is having more and more and finally (if possible) all within device-tree and dynamic configuration rather than in #define ... cheers, Hannes