于 2017年8月6日 GMT+08:00 上午10:39:54, Chen-Yu Tsai <w...@csie.org> 写到: >On Sat, Aug 05, 2017 at 05:35:55AM +0800, Icenowy Zheng wrote: >> The configuration struct of A64 EMMC(MMC2) compatible used to >> have the needs_new_timings variable missing, which lead to NULL >> pointer dereference now when trying to set up the old timings mode, >as >> the old timings mode doesn't exist at all on A64. > >I'm not familiar with the A64's eMMC controller. The datasheet says >it does not have the timing switch register. It does not say whether >it is always in the old or new timing mode. "needs_new_timings" >probably meant that the switch has to be set.
As I know, it supports DDR mode, but the CCU has no clk delays. So it should be the new timings mode. > >This fix doesn't really fix the underlying issue, which is the check >for clk_delays was incorrectly replaced. sun4i/sun5i is also broken. > >Could you try this patch instead: > ><--- > >From 23b841a11294cb6a0cf1e146616b068f60c2ec7d Mon Sep 17 00:00:00 2001 >From: Chen-Yu Tsai <w...@csie.org> >Date: Sun, 6 Aug 2017 10:24:47 +0800 >Subject: [PATCH] mmc: sunxi: Fix NULL pointer reference on clk_delays > >Some SoCs do not support clk delays for MMC in the clock control unit. >These include the old controllers in A10/A10s/A13/R8, and the new eMMC >controller in A64. The config structure for these controllers do not >specify clk_delays, but the check for this was replaced in commit >b0600daebf31 ("mmc: sunxi: Support controllers that can use both old >and new timings"). > >This patch adds back the check for clk_delays, and also adds comments >for both checks in sunxi_mmc_clk_set_phase(). > >Fixes: b0600daebf31 ("mmc: sunxi: Support controllers that can use > both old and new timings") >Signed-off-by: Chen-Yu Tsai <w...@csie.org> >--- > drivers/mmc/host/sunxi-mmc.c | 5 +++++ > 1 file changed, 5 insertions(+) > >diff --git a/drivers/mmc/host/sunxi-mmc.c >b/drivers/mmc/host/sunxi-mmc.c >index 3777517982dd..020547e5fa45 100644 >--- a/drivers/mmc/host/sunxi-mmc.c >+++ b/drivers/mmc/host/sunxi-mmc.c >@@ -722,9 +722,14 @@ static int sunxi_mmc_clk_set_phase(struct >sunxi_mmc_host *host, > { > int index; > >+ /* No need to set clk controller delays under new timings */ > if (host->use_new_timings) > return 0; > >+ /* Some old controllers don't support delays */ >+ if (!host->cfg->clk_delays) >+ return 0; >+ > /* determine delays */ > if (rate <= 400000) { > index = SDXC_CLK_400K; -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.