Hi,
On 27-01-2020 12:57, Adrian Hunter wrote:
On 27/01/20 1:37 pm, Ulf Hansson wrote:
+ Adrian
Is this the same as:
https://lore.kernel.org/linux-mmc/20200108093903.57620-2-hdegoede@xxxxxxxxxx/
Yes the device from:
https://bugzilla.kernel.org/show_bug.cgi?id=202459
Seems to be the exact same one as the one where I'm seeing this problem
and presumably the fix I wrote should work for that one too.
As discussed I still need to try an alternative fix. I hope to get around
to that sometimes during the coming 2-3 days.
Regards,
Hans
On Thu, 23 Jan 2020 at 11:40, Tim Schumacher <tim@xxxxxxxxxx> wrote:
On 2019-09-06, Ulf Hansson wrote:
On Thu, 5 Sep 2019 at 22:01, Tim Schumacher <tim@xxxxxxxxxx> wrote:
Hi,
I'm sending this old bug by mail since a lot of developers don't use
bugzilla.
Original bug report on bugzilla by Pedro Rodrigues from 2019-01-30:
https://bugzilla.kernel.org/show_bug.cgi?id=202459
This bug can be found on a Lenovo Miix 320-10ICR
When using a SDXC (UHS) card, the screen becomes black if
_mmc_sd_resume() is called. After some investigation, I found that an
UHS card uses 1.8 V for signalling while a normal SD card uses 3.3 V. By
forcing the SDXC to use 3.3 V the black screen does not appear. It seems
that during a _mmc_sd_resume function call, while claiming the host, an
I2C resume function is called based on an existing supplier link between
the I2C bus and the card device. The problem is that if the signalling
voltage is configured to 1.8 V, during the I2C resume call, the screen
turns black. I was able to fix this issue by setting the initial signal
voltage (3.3 V) before suspending the card, so that when the card is
resumed, the voltage is in the original state. To do this I added a
function call to mmc_set_initial_signal_voltage() during mmc_power_off
routine (drivers/mmc/core/core.c). As I’m not an expert on Linux, I’m
posting the issue and possible solution so that it could be implemented
on a future release.
Please, share your thoughts :)
I can't provide further insight but I'm interested if this is possibly
the cause for the general issues people are having with the SD card
reader on Lenovo Miix 320 devices.
Those issues described in posts like
https://vincent-ventures.com/2018/12/arch-linux-on-lenovo-ideapad-miix-320/
https://esc.sh/blog/linux-on-lenovo-miix-320/
are (1) black screen when booting with an SD card installed and (2) when
inserting an SD card after booting it shows up but upon trying to access
it the screen turns black until the card is removed again.
I can confirm (1) on my Lenovo Miix 320-10ICR with kernel version
5.2.11. I can also confirm that only SDXC cards are affected, SD and
SDHC cards work as expected.
For the mmc community to help, you need to provide some kernel logs,
output from lspci, figure out what mmc host driver that is being used,
etc - in general collect more data. Then re-post the data to
linux-mmc, me and a potential mmc host driver maintainer (if there is
one). Yes, we can look into bugzilla as well, but first we need some
more overall info in an email.
Most likely, if there is any response, you will be asked to test
patches. So you need to be able build and boot a new kernel, but I
guess you already know that part.
Kind regards
Uffe
Hi, I'm coming back to this issue now. The issue is still present in
kernel version 5.4.8.
Kernel logs from boot with SD card and black screen: https://termbin.com/outp
Kernel logs from boot without SD card: https://termbin.com/dc2y
I couldn't find anything conspicuous in there, the card is working as
expected. Only issue is the black screen (I'm doing these tests via SSH).
lspci output: https://termbin.com/x452
How do I figure out which mmc host driver is in use? I assume I'm
looking for one of these https://github.com/torvalds/linux/tree/master/drivers/mmc/host
I couldn't find anything like it in the kernel logs or from lsmod.
Please read the original bug report by Pedro Rodrigues quoted above.
He got to the technical core of the problem already and proposed a fix
I assume could be understood, sanity checked and implemented by a mmc
maintainer.
I have read the reports and browsed the data you provided. It seems
like this is an sdhci-acpi mmc/sd controller, Adrian Hunter (Intel
maintains this variant). There is one eMMC, which seems to work fine
and then the SD-card that you have inserted. The SD card looks like it
gets detected properly.
I don't see anything in the logs that stands out. However, I would try
a couple of different SD-cards, just to see what happens (if you have
more then one at hand). From that and going forward, I think I will
need to defer to Adrian's help. Perhaps we can put together some debug
patch for you to test, or so.
I will keep monitoring the discussion and fold in if there is anything
more I can help with.
Kind regards
Uffe
