Hi Lee,
On Tue, 07 Jun 2016, Lee Jones wrote:
> On Tue, 07 Jun 2016, Peter Griffin wrote:
>
> > mmc_select_bus_width() returns bus width (4 or 8) on success or
> > zero if unsupported. If bus width is set successfully we then wish
> > to switch to HS200 mode.
> >
> > This avoids the following error message in v4.70-rc2
> >
> > [ 2.523674] mmc0: mmc_select_hs200 failed, error 3
> > [ 2.528516] mmc0: error 3 whilst initialising MMC card
> >
> > With this patch card is enumerated correctly
> >
> > [ 2.468065] mmc0: new HS200 MMC card at address 0001
> > [ 2.468335] mmcblk0: mmc0:0001 P1XXXX 7.20 GiB
> > [ 2.468441] mmcblk0boot0: mmc0:0001 P1XXXX partition 1 2.00 MiB
> > [ 2.468552] mmcblk0boot1: mmc0:0001 P1XXXX partition 2 2.00 MiB
> > [ 2.468651] mmcblk0rpmb: mmc0:0001 P1XXXX partition 3 128 KiB
> > [ 2.469269] mmcblk0: p1
> >
> > Fixes: 287980e (remove lots of IS_ERR_VALUE abuses)
> > Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> > drivers/mmc/core/mmc.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> > index c984321..aafb73d 100644
> > --- a/drivers/mmc/core/mmc.c
> > +++ b/drivers/mmc/core/mmc.c
> > @@ -1276,7 +1276,7 @@ static int mmc_select_hs200(struct mmc_card *card)
> > * switch to HS200 mode if bus width is set successfully.
> > */
> > err = mmc_select_bus_width(card);
> > - if (!err) {
> > + if (err > 0) {
> > val = EXT_CSD_TIMING_HS200 |
> > card->drive_strength << EXT_CSD_DRV_STR_SHIFT;
> > err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> > @@ -1583,7 +1583,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
> > } else if (mmc_card_hs(card)) {
> > /* Select the desired bus width optionally */
> > err = mmc_select_bus_width(card);
> > - if (!err) {
> > + if (err > 0) {
> > err = mmc_select_hs_ddr(card);
> > if (err)
> > goto free_card;
>
> Looks like this has already been 'fixed' in -rc2.
Ah, it seems I was on -rc1, not -rc2
>
> Although, this patch does not work for me.
> mmc: fix mmc mode selection for HS-DDR and higher
>
> When IS_ERR_VALUE was removed from the mmc core code, it was replaced
> with a simple not-zero check. This does not work, as the value checked
> is the return value for mmc_select_bus_width, which returns the set
> bit width on success. This made eMMC modes higher than HS-DDR unusable.
>
> Fix this by checking for a positive return value instead.
>
> Fixes: 287980e49ffc ("remove lots of IS_ERR_VALUE abuses")
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
> Acked-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> Acked-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
> Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> Tested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index c984321..5d438ad 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1276,7 +1276,7 @@ static int mmc_select_hs200(struct mmc_card *card)
> * switch to HS200 mode if bus width is set successfully.
> */
> err = mmc_select_bus_width(card);
> - if (!err) {
> + if (err >= 0) {
This patch looks wrong to me, as if zero is returned by mmc_select_bus_width() it
means setting the bus width failed, and you most likely don't want to switch to
hs200 mode.
Ulf - what is your opinion?
regards,
Peter.>
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