From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludovic.desroches@atmel.com (ludovic.desroches at atmel.com) Date: Wed, 28 Mar 2012 12:28:33 +0200 Subject: [PATCH v2 1/3] mmc: atmel-mci: correct data timeout computation In-Reply-To: <1332344483-3915-2-git-send-email-ludovic.desroches@atmel.com> References: <1332344483-3915-2-git-send-email-ludovic.desroches@atmel.com> Message-ID: <1332930513-14893-1-git-send-email-ludovic.desroches@atmel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Ludovic Desroches 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: Ludovic Desroches Cc: stable --- drivers/mmc/host/atmel-mci.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index e4449a5..3a57964 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -480,7 +480,14 @@ err: 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, -- 1.7.5.4