On 7/1/20 7:22 PM, Ming Lei wrote:

On Wed, Jul 01, 2020 at 04:16:32PM +0200, Marek Szyprowski wrote:

quoted

Hi Ming,

On 01.07.2020 15:45, Ming Lei wrote:

quoted

On Wed, Jul 01, 2020 at 03:01:03PM +0200, Marek Szyprowski wrote:

quoted

On 29.06.2020 11:47, Ming Lei wrote:

quoted

It is natural to release driver tag when this request is completed by
LLD or device since its purpose is for LLD use.

One big benefit is that the released tag can be re-used quicker since
bio_endio() may take too long.

Meantime we don't need to release driver tag for flush request.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <redacted>

This patch landed recently in linux-next as commit 36a3df5a4574. Sadly
it causes a regression on one of my test systems (ARM 32bit, Samsung
Exynos5422 SoC based Odroid XU3 board with eMMC). The system boots fine
and then after a few seconds every executed command hangs. No
panic/ops/any other message. I will try to provide more information asap
I find something to share. Simple reverting it in linux-next is not
possible due to dependencies.

What is the exact eMMC's driver code(include the host driver)?

dwmmc-exynos (drivers/mmc/host/dw_mmc-exynos.c)

Hi,

Just take a quick look at mmc code, there are only two req->tag
consumers:

Just a heads up that I've queued up a revert of the offending commits.
It's not just this issue, there's also another one reported with
swapping.

-- 
Jens Axboe