Hello Ulf, On Thu, 2018-03-15 at 10:57 +0100, Ulf Hansson wrote: > On 14 March 2018 at 20:30, Evgeniy Didin <Evgeniy.Didin@xxxxxxxxxxxx> 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://urldefense.proofpoint.com/v2/url?u=https-3A__www.spinics.net_lists_linux-2Dmmc_msg48125.html&d=DwIBaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=vQk-RIbjwN0zvlwiMSpq3LYUTNf7Gqc4ujhosYI > > TtAw&m=6rPWpKUYQD3kY-2OEikJUWyEJvwKJljWHFC8rd2TCak&s=JjX0Dx8-eSyW2cATMsnG1eAzrKgoDkS1bcS5XYrVtlE&e=. > > Evgeniy, > > It seems like I should squash this fix into the above commit? Makes sense? IMHO it is not a good idea, because this fix is orthogonal to the above commit. Debugging drto overflow issue we found this strange behavior. This might be general issue of soft-reset. So I think this should be separate patch. Also if these patches are independent, it will be easier to backport them. Best regards, Evgeniy Didin > 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@xxxxxxxxxxxx> > > Cc: Jaehoon Chung <jh80.chung@xxxxxxxxxxx> > > Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > > Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > > Cc: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx> > > Cc: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> > > Cc: Alexey Brodkin <abrodkin@xxxxxxxxxxxx> > > Cc: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> > > Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx > > --- > > 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 > > ��.n��������+%������w��{.n�����{��i��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
