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

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
...@@ -482,7 +482,14 @@ static void atmci_init_debugfs(struct atmel_mci_slot *slot) ...@@ -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, static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host,
unsigned int ns) 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, static void atmci_set_timeout(struct atmel_mci *host,
......
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