On 02/04/2014 06:44 AM, Balaji T K wrote:

On Tuesday 21 January 2014 04:59 AM, Nishanth Menon wrote:

quoted

When device is booted using devicetree, platforms impacted by
Erratum 2.1.1.128 is not detected easily in the mmc driver. This erratum
indicates that the module cannot do multi-block transfers.

Handle this by providing a boolean flag to indicate to driver that it is
working on a hardware with mentioned limitation.

Signed-off-by: Nishanth Menon <nm@ti.com>
---

This explains the logs I see:
OMAP3430 LDP (ES2.2):
	uImage only boot:  http://slexy.org/raw/s2YrbMAi7c
	uImage+dtb concatenated boot: http://slexy.org/raw/s20qVg17T0

With the following flag set, device is now able to consistently boot with
device tree supported uImage+dtb concat boot.

  .../devicetree/bindings/mmc/ti-omap-hsmmc.txt      |    2 ++
  drivers/mmc/host/omap_hsmmc.c                      |    3 +++
  2 files changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
index 8c8908a..ab36f8b 100644
--- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
+++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt

@@ -26,6 +26,8 @@ specifier is required.
  dma-names: List of DMA request names. These strings correspond
  1:1 with the DMA specifiers listed in dmas. The string naming is
  to be "rx" and "tx" for RX and TX DMA requests, respectively.
+ti,erratum-2.1.1.128: boolean, for OMAP3430/OMAP35xx platforms with broken
+multiblock reads

Rather than ti,errata.. specific property, something like
caps no/disable multiblock read is more readable in my opinion, Otherwise

Is'nt the better definition to state i have quirk X and allow the
driver to do the necessary thing/things needed to handle quirk X? in
this case, there is just one thing to do: broken multi_block_read, in
the case of other quirks, there might be more than 1 thing to do.. let
driver figure that out, dts just states the h/w capabilty or in this
case, the quirk capability.

Acked-by: Balaji T K <redacted>

quoted

  Examples:

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 014bfe5..f2d5940 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c

@@ -1730,6 +1730,9 @@ static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev)
  	if (of_find_property(np, "ti,dual-volt", NULL))
  		pdata->controller_flags |= OMAP_HSMMC_SUPPORTS_DUAL_VOLT;

+	if (of_find_property(np, "ti,erratum-2.1.1.128", NULL))
+		pdata->controller_flags |= OMAP_HSMMC_BROKEN_MULTIBLOCK_READ;
+
  	/* This driver only supports 1 slot */
  	pdata->nr_slots = 1;
  	pdata->slots[0].switch_pin = cd_gpio;

-- 
Regards,
Nishanth Menon