[U-Boot] [PATCH] Timeout for SDHCI commands

Eli Billauer
2014-06-12T09:41:08Z

The patch in the following mail is a result of a problem I had using an eMMC
device on a Xilinx Zynq ARM processor. It turned out that the waiting for a
certain response from the SDIO interface was made with a plain loop, with
no absolute time measurement. Since I'm using a relatively fast processor,
the timeout expired before the eMMC chip managed to acknowledge an
mmc_switch() with EXT_CSD_HS_TIMING.

This patch fixes the problem on my board, and eMMC works properly with it.
However I can't say that I really understand what I did, and the 100 ms
timeout was chosen with a finger in the wind. If there's a reason why the
timeout should be longer or shorter, this is a good time to come forward.

Thanks,
Eli

Eli Billauer (1):
mmc: sdhci: Fixed timeout for sdhci_send_command()

drivers/mmc/sdhci.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

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1.7.2.3