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Commit 66292ad9 authored by Ludovic Desroches's avatar Ludovic Desroches Committed by Chris Ball
Browse files

mmc: atmel-mci: correct data timeout computation 



The HSMCI operates at a rate of up to Master Clock divided by two.
Moreover previous calculation can cause overflows and so wrong
timeouts.

Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 9f4e8151

drivers/mmc/host/atmel-mci.c

+8 −1
Original line number Diff line number Diff line
@@ -482,7 +482,14 @@ static void atmci_init_debugfs(struct atmel_mci_slot *slot) 
static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host,

					unsigned int ns)

{

	return (ns * (host->bus_hz / 1000000) + 999) / 1000;

	/*

	 * It is easier here to use us instead of ns for the timeout,

	 * it prevents from overflows during calculation.

	 */

	unsigned int us = DIV_ROUND_UP(ns, 1000);



	/* Maximum clock frequency is host->bus_hz/2 */

	return us * (DIV_ROUND_UP(host->bus_hz, 2000000));

}



static void atmci_set_timeout(struct atmel_mci *host,