3.16.63-rc1 review patch. If anyone has any objections, please let me know.
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From: Aaro Koskinen aaro.koskinen@iki.fi
commit e8cde625bfe8a714a856e1366bcbb259d7346095 upstream.
Since v2.6.22 or so there has been reports [1] about OMAP MMC being broken on OMAP15XX based hardware (OMAP5910 and OMAP310). The breakage seems to have been caused by commit 46a6730e3ff9 ("mmc-omap: Fix omap to use MMC_POWER_ON") that changed clock enabling to be done on MMC_POWER_ON. This can happen multiple times in a row, and on 15XX the hardware doesn't seem to like it and the MMC just stops responding. Fix by memorizing the power mode and do the init only when necessary.
Before the patch (on Palm TE):
mmc0: new SD card at address b368 mmcblk0: mmc0:b368 SDC 977 MiB mmci-omap mmci-omap.0: command timeout (CMD18) mmci-omap mmci-omap.0: command timeout (CMD13) mmci-omap mmci-omap.0: command timeout (CMD13) mmci-omap mmci-omap.0: command timeout (CMD12) [x 6] mmci-omap mmci-omap.0: command timeout (CMD13) [x 6] mmcblk0: error -110 requesting status mmci-omap mmci-omap.0: command timeout (CMD8) mmci-omap mmci-omap.0: command timeout (CMD18) mmci-omap mmci-omap.0: command timeout (CMD13) mmci-omap mmci-omap.0: command timeout (CMD13) mmci-omap mmci-omap.0: command timeout (CMD12) [x 6] mmci-omap mmci-omap.0: command timeout (CMD13) [x 6] mmcblk0: error -110 requesting status mmcblk0: recovery failed! print_req_error: I/O error, dev mmcblk0, sector 0 Buffer I/O error on dev mmcblk0, logical block 0, async page read mmcblk0: unable to read partition table
After the patch:
mmc0: new SD card at address b368 mmcblk0: mmc0:b368 SDC 977 MiB mmcblk0: p1
The patch is based on a fix and analysis done by Ladislav Michl.
Tested on OMAP15XX/OMAP310 (Palm TE), OMAP1710 (Nokia 770) and OMAP2420 (Nokia N810).
[1] https://marc.info/?t=123175197000003&r=1&w=2
Fixes: 46a6730e3ff9 ("mmc-omap: Fix omap to use MMC_POWER_ON") Reported-by: Ladislav Michl ladis@linux-mips.org Reported-by: Andrzej Zaborowski balrogg@gmail.com Tested-by: Ladislav Michl ladis@linux-mips.org Acked-by: Tony Lindgren tony@atomide.com Signed-off-by: Aaro Koskinen aaro.koskinen@iki.fi Signed-off-by: Ulf Hansson ulf.hansson@linaro.org [bwh: Backported to 3.16: Set initial state to MMC_POWER_OFF instead of MMC_POWER_UNDEFINED] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/mmc/host/omap.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/mmc/host/omap.c +++ b/drivers/mmc/host/omap.c @@ -105,6 +105,7 @@ struct mmc_omap_slot { unsigned int vdd; u16 saved_con; u16 bus_mode; + u16 power_mode; unsigned int fclk_freq;
struct tasklet_struct cover_tasklet; @@ -1155,7 +1156,7 @@ static void mmc_omap_set_ios(struct mmc_ struct mmc_omap_slot *slot = mmc_priv(mmc); struct mmc_omap_host *host = slot->host; int i, dsor; - int clk_enabled; + int clk_enabled, init_stream;
mmc_omap_select_slot(slot, 0);
@@ -1165,6 +1166,7 @@ static void mmc_omap_set_ios(struct mmc_ slot->vdd = ios->vdd;
clk_enabled = 0; + init_stream = 0; switch (ios->power_mode) { case MMC_POWER_OFF: mmc_omap_set_power(slot, 0, ios->vdd); @@ -1172,13 +1174,17 @@ static void mmc_omap_set_ios(struct mmc_ case MMC_POWER_UP: /* Cannot touch dsor yet, just power up MMC */ mmc_omap_set_power(slot, 1, ios->vdd); + slot->power_mode = ios->power_mode; goto exit; case MMC_POWER_ON: mmc_omap_fclk_enable(host, 1); clk_enabled = 1; dsor |= 1 << 11; + if (slot->power_mode != MMC_POWER_ON) + init_stream = 1; break; } + slot->power_mode = ios->power_mode;
if (slot->bus_mode != ios->bus_mode) { if (slot->pdata->set_bus_mode != NULL) @@ -1194,7 +1200,7 @@ static void mmc_omap_set_ios(struct mmc_ for (i = 0; i < 2; i++) OMAP_MMC_WRITE(host, CON, dsor); slot->saved_con = dsor; - if (ios->power_mode == MMC_POWER_ON) { + if (init_stream) { /* worst case at 400kHz, 80 cycles makes 200 microsecs */ int usecs = 250;
@@ -1232,6 +1238,7 @@ static int mmc_omap_new_slot(struct mmc_ slot->host = host; slot->mmc = mmc; slot->id = id; + slot->power_mode = MMC_POWER_OFF; slot->pdata = &host->pdata->slots[id];
host->slots[id] = slot;