From 15b800d8f60d6f063d627de612f01794a29982ed Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Sun, 3 Feb 2019 00:14:33 +0200 Subject: mmc: omap: fix the maximum timeout setting commit a6327b5e57fdc679c842588c3be046c0b39cc127 upstream. When running OMAP1 kernel on QEMU, MMC access is annoyingly noisy: MMC: CTO of 0xff and 0xfe cannot be used! MMC: CTO of 0xff and 0xfe cannot be used! MMC: CTO of 0xff and 0xfe cannot be used! [ad inf.] Emulator warnings appear to be valid. The TI document SPRU680 [1] ("OMAP5910 Dual-Core Processor MultiMedia Card/Secure Data Memory Card (MMC/SD) Reference Guide") page 36 states that the maximum timeout is 253 cycles and "0xff and 0xfe cannot be used". Fix by using 0xfd as the maximum timeout. Tested using QEMU 2.5 (Siemens SX1 machine, OMAP310), and also checked on real hardware using Palm TE (OMAP310), Nokia 770 (OMAP1710) and Nokia N810 (OMAP2420) that MMC works as before. [1] http://www.ti.com/lit/ug/spru680/spru680.pdf Fixes: 730c9b7e6630f ("[MMC] Add OMAP MMC host driver") Signed-off-by: Aaro Koskinen Signed-off-by: Ulf Hansson Signed-off-by: Ben Hutchings --- drivers/mmc/host/omap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c index 1996467481e9..40e57398ad56 100644 --- a/drivers/mmc/host/omap.c +++ b/drivers/mmc/host/omap.c @@ -921,7 +921,7 @@ static inline void set_cmd_timeout(struct mmc_omap_host *host, struct mmc_reques reg &= ~(1 << 5); OMAP_MMC_WRITE(host, SDIO, reg); /* Set maximum timeout */ - OMAP_MMC_WRITE(host, CTO, 0xff); + OMAP_MMC_WRITE(host, CTO, 0xfd); } static inline void set_data_timeout(struct mmc_omap_host *host, struct mmc_request *req) -- cgit v1.2.3