On Sun, Oct 03, 2021 at 06:47:55PM +0300, Adrian Hunter wrote: > On 03/10/2021 16:58, Shawn Guo wrote: > > On Thu, Sep 30, 2021 at 01:00:03PM +0200, Ulf Hansson wrote: > >> On Sun, 26 Sept 2021 at 15:28, Shawn Guo <shawn.guo@xxxxxxxxxx> wrote: > >>> > >>> On Thundercomm TurboX CM2290, the eMMC OCR reports vdd = 23 (3.5 ~ 3.6 V), > >>> which is being treated as an invalid value by sdhci_set_power_noreg(). > >>> And thus eMMC is totally broken on the platform. > >>> > >>> [ 1.436599] ------------[ cut here ]------------ > >>> [ 1.436606] mmc0: Invalid vdd 0x17 > >>> [ 1.436640] WARNING: CPU: 2 PID: 69 at drivers/mmc/host/sdhci.c:2048 sdhci_set_power_noreg+0x168/0x2b4 > >>> [ 1.436655] Modules linked in: > >>> [ 1.436662] CPU: 2 PID: 69 Comm: kworker/u8:1 Tainted: G W 5.15.0-rc1+ #137 > >>> [ 1.436669] Hardware name: Thundercomm TurboX CM2290 (DT) > >>> [ 1.436674] Workqueue: events_unbound async_run_entry_fn > >>> [ 1.436685] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > >>> [ 1.436692] pc : sdhci_set_power_noreg+0x168/0x2b4 > >>> [ 1.436698] lr : sdhci_set_power_noreg+0x168/0x2b4 > >>> [ 1.436703] sp : ffff800010803a60 > >>> [ 1.436705] x29: ffff800010803a60 x28: ffff6a9102465f00 x27: ffff6a9101720a70 > >>> [ 1.436715] x26: ffff6a91014de1c0 x25: ffff6a91014de010 x24: ffff6a91016af280 > >>> [ 1.436724] x23: ffffaf7b1b276640 x22: 0000000000000000 x21: ffff6a9101720000 > >>> [ 1.436733] x20: ffff6a9101720370 x19: ffff6a9101720580 x18: 0000000000000020 > >>> [ 1.436743] x17: 0000000000000000 x16: 0000000000000004 x15: ffffffffffffffff > >>> [ 1.436751] x14: 0000000000000000 x13: 00000000fffffffd x12: ffffaf7b1b84b0bc > >>> [ 1.436760] x11: ffffaf7b1b720d10 x10: 000000000000000a x9 : ffff800010803a60 > >>> [ 1.436769] x8 : 000000000000000a x7 : 000000000000000f x6 : 00000000fffff159 > >>> [ 1.436778] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff > >>> [ 1.436787] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff6a9101718d80 > >>> [ 1.436797] Call trace: > >>> [ 1.436800] sdhci_set_power_noreg+0x168/0x2b4 > >>> [ 1.436805] sdhci_set_ios+0xa0/0x7fc > >>> [ 1.436811] mmc_power_up.part.0+0xc4/0x164 > >>> [ 1.436818] mmc_start_host+0xa0/0xb0 > >>> [ 1.436824] mmc_add_host+0x60/0x90 > >>> [ 1.436830] __sdhci_add_host+0x174/0x330 > >>> [ 1.436836] sdhci_msm_probe+0x7c0/0x920 > >>> [ 1.436842] platform_probe+0x68/0xe0 > >>> [ 1.436850] really_probe.part.0+0x9c/0x31c > >>> [ 1.436857] __driver_probe_device+0x98/0x144 > >>> [ 1.436863] driver_probe_device+0xc8/0x15c > >>> [ 1.436869] __device_attach_driver+0xb4/0x120 > >>> [ 1.436875] bus_for_each_drv+0x78/0xd0 > >>> [ 1.436881] __device_attach_async_helper+0xac/0xd0 > >>> [ 1.436888] async_run_entry_fn+0x34/0x110 > >>> [ 1.436895] process_one_work+0x1d0/0x354 > >>> [ 1.436903] worker_thread+0x13c/0x470 > >>> [ 1.436910] kthread+0x150/0x160 > >>> [ 1.436915] ret_from_fork+0x10/0x20 > >>> [ 1.436923] ---[ end trace fcfac44cb045c3a8 ]--- > >>> > >>> Fix the issue by mapping MMC_VDD_35_36 (and MMC_VDD_34_35) to > >>> SDHCI_POWER_330 as well. > >>> > >>> Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx> > >>> --- > >>> I'm not sure if this is the right solution, as I do not have SDHCI > >>> specification. Hence it's a RFC. > >>> > >>> drivers/mmc/host/sdhci.c | 2 ++ > >>> 1 file changed, 2 insertions(+) > >>> > >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > >>> index 8eefa7d5fe85..2427481535a3 100644 > >>> --- a/drivers/mmc/host/sdhci.c > >>> +++ b/drivers/mmc/host/sdhci.c > >>> @@ -2042,6 +2042,8 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode, > >>> break; > >>> case MMC_VDD_32_33: > >>> case MMC_VDD_33_34: > >>> + case MMC_VDD_34_35: > >>> + case MMC_VDD_35_36: > >>> pwr = SDHCI_POWER_330; > >> > >> The SDHCI specification doesn't state exactly what level > >> SDHCI_POWER_330 corresponds to. It's 3.3V typically. > >> > >> I don't have any strong opinion about this change, although I am a > >> little bit puzzled over why this solves the problem for you. > >> > >> Unless the host (sdhci) announces that it supports MMC_VDD_34_35 or > >> MMC_VDD_35_36 through its mmc->ocr_avail mask, the mmc core shouldn't > >> try to use it. Can you perhaps check what value the mmc->ocr_avail > >> gets assigned to in sdhci_setup_host() for your mmc host? > > > > Hi Ulf, > > > > Thanks for the comment! > > > > ocr_avail is 0xfff800, which is a result of mmc_regulator_get_ocrmask() > > call. On this platform, the vmmc has a 3.6V max voltage. I can enforce > > `regulator-max-microvolt` to be 3.3V to fix the problem, but I'm not > > sure it's more correct than this RFC change. > > The host controller lines are not necessarily connected directly to the > card, and the 3.3V selection is not necessarily actually 3.3V either. > So I have no problem with the change, but the question of whether it is > right for you really depends on your hardware. For the patch, I would > suggest adding a comment in the code, that the driver that allows > 3.4V-3.6V is assumed to know that the hardware supports it. Thanks for the suggestion, Adrian! Will do. Shawn
