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Opened 8 years ago

Last modified 4 years ago

#6848 new defect

MMC writing

Reported by: ILAH Owned by: developers
Priority: normal Milestone: Barrier Breaker 14.07
Component: other Version: Kamikaze trunk
Keywords: mmc sd freeze Cc:

Description

When copying many/large files to an SD Card on Fonera/OpenWRT 8.09/GPIO 13470 the cp command task and SSH terminal will freeze.
Same happens when writing a logfile generating many entries at a time.

On same hardware setup with OpenWRT 7.09 an "Phrozen Driver" writing went fine.

Is there a solution?

Attachments (0)

Change History (4)

comment:1 Changed 8 years ago by or4n9e@…

Minor correction: This issue applies to OpenWrt trunk (e.g. r19885, atheros), while the 8.09 branch is most likely affected as well.

comment:2 follow-up: Changed 8 years ago by florian

The mmc driver is really CPU intensive, and this is due to the use of GPIOs to access the MMC card, so there are little things one can do about this.

comment:3 in reply to: ↑ 2 Changed 8 years ago by anonymous

Replying to florian:

The mmc driver is really CPU intensive, and this is due to the use of GPIOs to access the MMC card, so there are little things one can do about this.

It makes perfect sense that bit-banging is very CPU intensive. We're just wondering why Kamikaze 7.09/Phrozen mmc works (to my knowledge bit-bang as well) while current Kamikaze trunk/mmc_over_gpio has the described issues on the very same hardware. Do you have any suggestions/optimization hints here? Or any clue for the reason of performance differences between Phrozen/mmc_over_gpio? Overclocking the CPU may help from your perspective?

Thanks in advance.

comment:4 Changed 4 years ago by jow

  • Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07

Milestone Attitude Adjustment 12.09 deleted

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