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From: Eli Billauer <eli.billauer@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] Timeout for SDHCI commands
Date: Thu, 12 Jun 2014 12:41:08 +0300	[thread overview]
Message-ID: <1402566069-8061-1-git-send-email-eli.billauer@gmail.com> (raw)

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(-)

-- 
1.7.2.3

             reply	other threads:[~2014-06-12  9:41 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-12  9:41 Eli Billauer [this message]
2014-06-12  9:41 ` [U-Boot] [PATCH] mmc: sdhci: Fixed timeout for sdhci_send_command() Eli Billauer
2014-06-19 16:43   ` Andy Fleming
2014-06-19 16:50     ` Eli Billauer
2014-06-27  9:37   ` Pantelis Antoniou
2014-07-01 18:11     ` Andy Fleming
2014-07-04 21:02     ` Steve Rae

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