From: Stephen Warren swarren@nvidia.com

Currently, get_device()/get_dev_hwpart() for MMC devices does not select an explicit HW partition unless the user explicitly requests one, i.e. by requesting device "mmc 0.0" rather than just "mmc 0". I think it makes more sense if the default is to select HW partition 0 (main data area) if the user didn't request a specific partition. Otherwise, the following happens, which feels wrong:

Select HW partition 1 (boot0): mmc dev 0 1

Attempts to access SW partition 1 on HW partition 1 (boot0), rather than SW partition 1 on HW partition 0 (main data area): ls mmc 0:1 /

With this patch, the second command above re-selects the main data area.

Many device types don't support HW partitions at all, so if HW partition 0 is selected (either explicitly or as the default) and there's no select_hwpart function, we simply skip attempting to select a HW partition.

Some MMC devices (i.e. SD cards) don't support HW partitions. However, this patch still works, since mmc_start_init() sets the current partition number to 0, and mmc_select_hwpart() succeeds if the requested partition is already selected.

Signed-off-by: Stephen Warren swarren@nvidia.com --- disk/part.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/disk/part.c b/disk/part.c index 2827089d8d5f..b3097e32f0eb 100644 --- a/disk/part.c +++ b/disk/part.c @@ -86,7 +86,7 @@ block_dev_desc_t *get_dev_hwpart(const char *ifname, int dev, int hwpart) block_dev_desc_t *dev_desc = reloc_get_dev(dev); if (!dev_desc) return NULL; - if (hwpart == -1) + if (hwpart == 0 && !select_hwpart) return dev_desc; if (!select_hwpart) return NULL; @@ -102,7 +102,7 @@ block_dev_desc_t *get_dev_hwpart(const char *ifname, int dev, int hwpart)

block_dev_desc_t *get_dev(const char *ifname, int dev) { - return get_dev_hwpart(ifname, dev, -1); + return get_dev_hwpart(ifname, dev, 0); } #else block_dev_desc_t *get_dev_hwpart(const char *ifname, int dev, int hwpart) @@ -460,7 +460,7 @@ int get_device(const char *ifname, const char *dev_hwpart_str, hwpart_str++; } else { dev_str = dev_hwpart_str; - hwpart = -1; + hwpart = 0; }

dev = simple_strtoul(dev_str, &ep, 16);

Hi Stephen,

On May 23, 2014, at 9:48 PM, Stephen Warren wrote:

From: Stephen Warren swarren@nvidia.com

Currently, "mmc dev 0" does not change the selected HW partition. I think it makes more sense if "mmc dev 0" is an alias for "mmc dev 0 0", i.e. that HW partition 0 (main data area) is always selected by default if the user didn't request a specific partition. Otherwise, the following happens, which feels wrong:

Select HW partition 1 (boot0): mmc dev 0 1

Doesn't change the HW partition, so it's still 1 (boot0): mmc dev 0

With this patch, the second command above re-selects the main data area.

Note that some MMC devices (i.e. SD cards) don't support HW partitions. However, this patch still works, since mmc_start_init() sets the current partition number to 0, and mmc_select_hwpart() succeeds if the requested partition is already selected.

Signed-off-by: Stephen Warren swarren@nvidia.com

This series depends on "mmc: return meaningful error codes from mmc_select_hwpart" (which I just sent) for context.

common/cmd_mmc.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c index eea337506c3f..9e6a26fe62a2 100644 --- a/common/cmd_mmc.c +++ b/common/cmd_mmc.c @@ -403,7 +403,7 @@ static int do_mmc_part(cmd_tbl_t *cmdtp, int flag, static int do_mmc_dev(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) {

• int dev, part = -1, ret;

• int dev, part = 0, ret; struct mmc *mmc;

  if (argc == 1) {

@@ -426,13 +426,12 @@ static int do_mmc_dev(cmd_tbl_t *cmdtp, int flag, if (!mmc) return CMD_RET_FAILURE;

• if (part != -1) {

• ret = mmc_select_hwpart(dev, part);
  

• printf("switch to partitions #%d, %s\n",
  

• 	part, (!ret) ? "OK" : "ERROR");
  

• if (ret)
  

• 	return 1;
  

• }

• ret = mmc_select_hwpart(dev, part);
• printf("switch to partitions #%d, %s\n",

•       part, (!ret) ? "OK" : "ERROR");
  

• if (ret)

• return 1;
  

• curr_device = dev; if (mmc->part_config == MMCPART_NOAVAILABLE) printf("mmc%d is current device\n", curr_device);

-- 1.8.1.5

There's a small behavioral change (always selecting a hardware partition when selecting a device), but there shouldn't be any users that care about it.

Thanks, applied.

-- Pantelis

Acked-by: Pantelis Antoniou panto@antoniou-consulting.com