On 14 March 2018 at 20:30, Evgeniy Didin <Evgeniy.Didin at synopsys.com> wrote: > It was found that in IDMAC mode after soft-reset driver switches > to PIO mode. > > That's what happens in case of DTO timeout overflow calculation failure: > 1. soft-reset is called > 2. driver restarts dma > 3. descriptors states are checked, one of descriptor is owned by the IDMAC. > 4. driver can't use DMA and then switches to PIO mode. > > Failure was already fixed in: > https://www.spinics.net/lists/linux-mmc/msg48125.html. Evgeniy, It seems like I should squash this fix into the above commit? Makes sense? Kind regards Uffe > > Behaviour while soft-reset is not something we except or > even want to happen. So we switch from dw_mci_idmac_reset > to dw_mci_idmac_init, so descriptors are cleaned before starting dma. > > And while at it explicitly zero des0 which otherwise might > contain garbage as being allocated by dmam_alloc_coherent(). > > Signed-off-by: Evgeniy Didin <Evgeniy.Didin at synopsys.com> > Cc: Jaehoon Chung <jh80.chung at samsung.com> > Cc: Ulf Hansson <ulf.hansson at linaro.org> > Cc: Andy Shevchenko <andy.shevchenko at gmail.com> > Cc: Jisheng Zhang <Jisheng.Zhang at synaptics.com> > Cc: Shawn Lin <shawn.lin at rock-chips.com> > Cc: Alexey Brodkin <abrodkin at synopsys.com> > Cc: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com> > Cc: linux-snps-arc at lists.infradead.org > --- > drivers/mmc/host/dw_mmc.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 0aa39975f33b..26f2ac107702 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -558,6 +558,7 @@ static int dw_mci_idmac_init(struct dw_mci *host) > (sizeof(struct idmac_desc_64addr) * > (i + 1))) >> 32; > /* Initialize reserved and buffer size fields to "0" */ > + p->des0 = 0; > p->des1 = 0; > p->des2 = 0; > p->des3 = 0; > @@ -580,6 +581,7 @@ static int dw_mci_idmac_init(struct dw_mci *host) > i++, p++) { > p->des3 = cpu_to_le32(host->sg_dma + > (sizeof(struct idmac_desc) * (i + 1))); > + p->des0 = 0; > p->des1 = 0; > } > > @@ -1795,8 +1797,8 @@ static bool dw_mci_reset(struct dw_mci *host) > } > > if (host->use_dma == TRANS_MODE_IDMAC) > - /* It is also recommended that we reset and reprogram idmac */ > - dw_mci_idmac_reset(host); > + /* It is also required that we reinit idmac */ > + dw_mci_idmac_init(host); > > ret = true; > > -- > 2.11.0 >
