Re: [PATCH v3 0/7] mmc: bcm2835: Add new driver for the sdhost controller

[Gerd Hoffmann]

  Hi,

> First the flipping of the mmc host driver for the SD card slot will
> cause issues for users that build it as a module. When I tested this
> on Fedora the first update I ended up with a system that didn't boot.

Yep, switching drivers is a pain point here indeed.

Possibly we could fix that by adding a MODULE_SOFTDEP() to the iproc
driver?  Comments?  Better ideas?

> Also i often see the device hang for a long period when systemd probes
> for rfkill status, sometimes it needs to be reset but it generally
> gets there.

What device is that?  rpi3 with wifi?

> [    6.529079] Hardware name: Generic DT based system
> [    6.529106] [<c0311708>] (unwind_backtrace) from [<c030c438>]
> (show_stack+0x18/0x1c)
> [    6.529122] [<c030c438>] (show_stack) from [<c0639b44>]
> (dump_stack+0x80/0xa0)
> [    6.529137] [<c0639b44>] (dump_stack) from [<c034ca3c>] (__warn+0xe4/0x104)
> [    6.529150] [<c034ca3c>] (__warn) from [<c034ca98>]
> (warn_slowpath_fmt+0x3c/0x4c)
> [    6.529166] [<c034ca98>] (warn_slowpath_fmt) from [<c0363b2c>]
> (check_flush_dependency+0xac/0x134)
> [    6.529184] [<c0363b2c>] (check_flush_dependency) from [<c036433c>]
> (flush_work+0xa0/0x178)
> [    6.529201] [<c036433c>] (flush_work) from [<c0458084>]
> (drain_all_pages+0x1a8/0x1cc)
> [    6.529221] [<c0458084>] (drain_all_pages) from [<c04b1d90>]
> (start_isolate_page_range+0x168/0x1b4)
> [    6.529239] [<c04b1d90>] (start_isolate_page_range) from
> [<c045b854>] (alloc_contig_range+0xd4/0x314)
> [    6.529258] [<c045b854>] (alloc_contig_range) from [<c04b6660>]
> (cma_alloc+0x188/0x300)
> [    6.529275] [<c04b6660>] (cma_alloc) from [<c03161e8>]
> (__alloc_from_contiguous+0x40/0xd8)
> [    6.529290] [<c03161e8>] (__alloc_from_contiguous) from
> [<c03162bc>] (cma_allocator_alloc+0x3c/0x44)
> [    6.529303] [<c03162bc>] (cma_allocator_alloc) from [<c0316504>]
> (__dma_alloc+0x1d4/0x2f0)
> [    6.529317] [<c0316504>] (__dma_alloc) from [<c0316698>]
> (arm_dma_alloc+0x3c/0x48)
> [    6.529331] [<c0316698>] (arm_dma_alloc) from [<c049d120>]
> (dma_pool_alloc+0x124/0x240)
> [    6.529356] [<c049d120>] (dma_pool_alloc) from [<bf009568>]
> (bcm2835_dma_create_cb_chain+0xb0/0x1dc [bcm2835_dma])
> [    6.529385] [<bf009568>] (bcm2835_dma_create_cb_chain
> [bcm2835_dma]) from [<bf009ad4>] (bcm2835_dma_prep_slave_sg+0xf0/0x25c
> [bcm2835_dma])
> [    6.529418] [<bf009ad4>] (bcm2835_dma_prep_slave_sg [bcm2835_dma])
> from [<bf04af04>] (bcm2835_request+0x2a4/0x3f4 [bcm2835])
> [    6.529548] [<bf04af04>] (bcm2835_request [bcm2835]) from
> [<bf0145d0>] (mmc_start_request+0x1f8/0x264 [mmc_core])
> [    6.529756] [<bf0145d0>] (mmc_start_request [mmc_core]) from
> [<bf016204>] (mmc_start_areq+0x2c8/0x318 [mmc_core])
> [    6.529890] [<bf016204>] (mmc_start_areq [mmc_core]) from
> [<bf07fa1c>] (mmc_blk_issue_rw_rq+0xc0/0x308 [mmc_block])
> [    6.529943] [<bf07fa1c>] (mmc_blk_issue_rw_rq [mmc_block]) from
> [<bf080f84>] (mmc_blk_issue_rq+0x418/0x428 [mmc_block])
> [    6.529997] [<bf080f84>] (mmc_blk_issue_rq [mmc_block]) from
> [<bf081138>] (mmc_queue_thread+0x148/0x1bc [mmc_block])
> [    6.530031] [<bf081138>] (mmc_queue_thread [mmc_block]) from
> [<c036ae30>] (kthread+0x120/0x138)
> [    6.530049] [<c036ae30>] (kthread) from [<c0307e58>]
> (ret_from_fork+0x14/0x3c)
> [    6.530055] ---[ end trace 221a5a14ca55fa22 ]---
> [    6.545765]  mmcblk0: p1 p2 p3 p4
> [    6.566015] random: fast init done
> [    6.623699] mmc1: new high speed SDIO card at address 0001

Looks more like a cma allocator issue on a quick glance.

cheers,
  Gerd