Re: [PATCH 0/4] mmc: meson-gx: chained descriptor fixup and improvements

From: Kevin Hilman
Date: Thu Dec 06 2018 - 23:14:33 EST


Jerome Brunet <jbrunet@xxxxxxxxxxxx> writes:

> The goal of the patchset was mainly to address the following warning:
>
> WARNING: CPU: 0 PID: 0 at /usr/src/kernel/drivers/mmc/host/meson-gx-mmc.c:1025 meson_mmc_irq+0xc0/0x1e0
> Modules linked in: crc32_ce crct10dif_ce ipv6 overlay
> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.19.1 #1
> Hardware name: Some A113 Board (DT)
> pstate: 40000085 (nZcv daIf -PAN -UAO)
> pc : meson_mmc_irq+0xc0/0x1e0
> lr : __handle_irq_event_percpu+0x70/0x180
> sp : ffff000008003980
> x29: ffff000008003980 x28: 0000000000000000
> [...]
> x1 : ffff80001a71bd40 x0 : 0000000000000000
> Call trace:
> meson_mmc_irq+0xc0/0x1e0
> __handle_irq_event_percpu+0x70/0x180
> handle_irq_event_percpu+0x34/0x88
> handle_irq_event+0x48/0x78
> handle_fasteoi_irq+0xa0/0x180
> generic_handle_irq+0x24/0x38
> __handle_domain_irq+0x5c/0xb8
> gic_handle_irq+0x58/0xa8
>
> This happens when using the chained descriptor mode. If there is an
> error, we call mmc_request_done(), loosing any reference to the cmd. It
> turns out that the chained descriptor does really stops when we do so, at

I think you mean...

s/does really stops/does not really stop/

> least not completly. Most of the time, it can be seen with this harmless
> warning because the descriptor will raise another unexpected IRQ. On rare
> occasion, it will completly break the MMC.
>
> This is mostly adressed by patch #1.
> With this fixed, I took (yet) another look at the ultra-high speed modes
> and the tuning.
>
> I came up with new settings in patch 3 and 4. I've tested them on eMMC,
> sdcard and sdio on the following platforms:
> * gxbb p200
> * gxl p230, libretech (eMMC only), kvim.
> * axg s400
>
> So far, these new settings seems to be working great but I think it
> would be nice if others could test this and provide their feedback.
> This why patch 3 and 4 are RFT tagged.

For broader testing, I've added this to my v4.21/testing branch, which
is included in my integ branch which gets a spin through kernelCI.

Kevin