On Mon, Feb 04, 2019 at 06:16:24PM +0800, Chen-Yu Tsai wrote: > On Mon, Feb 4, 2019 at 5:34 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote: > > > > On Sun, Feb 03, 2019 at 11:56:27PM +0800, Chen-Yu Tsai wrote: > > > The MMC device tree bindings include properties used to signal various > > > signalling speed modes. Until now the sunxi driver was accepting them > > > without any further filtering, while the sunxi device trees were not > > > actually using them. > > > > > > Since some of the H5 boards can not run at higher speed modes stably, > > > we are resorting to declaring the higher speed modes per-board. > > > > > > Regardless, having boards declare modes and blindly following them, > > > even without proper support in the driver, is generally a bad thing. > > > > > > Filter out all unsupported modes from the capabilities mask after > > > the device tree properties have been parsed. > > > > > > Cc: <stable@xxxxxxxxxxxxxxx> > > > Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx> > > > > > > --- > > > > > > This should be backported to stable kernels in case people try to run > > > new device trees (that declare newly supported modes) with old kernels. > > > --- > > > drivers/mmc/host/sunxi-mmc.c | 16 ++++++++++++++++ > > > 1 file changed, 16 insertions(+) > > > > > > diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c > > > index 7415af8c8ff6..a01433012db0 100644 > > > --- a/drivers/mmc/host/sunxi-mmc.c > > > +++ b/drivers/mmc/host/sunxi-mmc.c > > > @@ -1415,6 +1415,22 @@ static int sunxi_mmc_probe(struct platform_device *pdev) > > > if (ret) > > > goto error_free_dma; > > > > > > + /* > > > + * If we don't support delay chains in the SoC, we can't use any > > > + * of the DDR speed modes. Mask them out in case the device > > > + * tree specifies the properties for them, which gets added to > > > + * the caps by mmc_of_parse() above. > > > + */ > > > + if (!(host->cfg->clk_delays || host->use_new_timings)) > > > + mmc->caps &= ~(MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR | > > > + MMC_CAP_1_2V_DDR); > > > + > > > + /* TODO: UHS modes untested due to lack of supporting boards */ > > > + mmc->caps &= ~MMC_CAP_UHS; > > > > I've tested up to SDR104 and it works on the A64 at least > > That's good to know. What board was this on? I had given up hope waiting > for a vendor to produce a board that could do proper voltage switching for > SD cards. On a Sootech SoM, that had an HS400 eMMC and an SDR104 Marvell WiFi chip. I don't have that board anymore, and the website seems down now though :/ > > > + /* TODO: This driver doesn't support HS200 and HS400 modes yet */ > > > + mmc->caps2 &= ~(MMC_CAP2_HS200 | MMC_CAP2_HS400); > > > > And HS200 works too. > > OK. I thought there was some special magic required in the driver. Maybe > that was for HS400 only? Again, what board was this on? Yeah, that was for HS400 only Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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