From: Finn Thain fthain@telegraphics.com.au
[ Upstream commit 931fc82a6aaf4e2e4a5490addaa6a090d78c24a7 ]
When writing values to the IOP status/control register make sure those values do not have any extraneous bits that will clear interrupt flags.
To place the SCC IOP into bypass mode would be desirable but this is not achieved by writing IOP_DMAINACTIVE | IOP_RUN | IOP_AUTOINC | IOP_BYPASS to the control register. Drop this ineffective register write.
Remove the flawed and unused iop_bypass() function. Make use of the unused iop_stop() function.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain fthain@telegraphics.com.au Tested-by: Stan Johnson userm57@yahoo.com Cc: Joshua Thompson funaho@jurai.org Link: https://lore.kernel.org/r/09bcb7359a1719a18b551ee515da3c4c3cf709e6.159088033... Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/m68k/mac/iop.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/arch/m68k/mac/iop.c b/arch/m68k/mac/iop.c index fb61af5ac4ab8..0b94f6672c5f3 100644 --- a/arch/m68k/mac/iop.c +++ b/arch/m68k/mac/iop.c @@ -183,7 +183,7 @@ static __inline__ void iop_writeb(volatile struct mac_iop *iop, __u16 addr, __u8
static __inline__ void iop_stop(volatile struct mac_iop *iop) { - iop->status_ctrl &= ~IOP_RUN; + iop->status_ctrl = IOP_AUTOINC; }
static __inline__ void iop_start(volatile struct mac_iop *iop) @@ -191,14 +191,9 @@ static __inline__ void iop_start(volatile struct mac_iop *iop) iop->status_ctrl = IOP_RUN | IOP_AUTOINC; }
-static __inline__ void iop_bypass(volatile struct mac_iop *iop) -{ - iop->status_ctrl |= IOP_BYPASS; -} - static __inline__ void iop_interrupt(volatile struct mac_iop *iop) { - iop->status_ctrl |= IOP_IRQ; + iop->status_ctrl = IOP_IRQ | IOP_RUN | IOP_AUTOINC; }
static int iop_alive(volatile struct mac_iop *iop) @@ -244,7 +239,6 @@ void __init iop_preinit(void) } else { iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA; } - iop_base[IOP_NUM_SCC]->status_ctrl = 0x87; iop_scc_present = 1; } else { iop_base[IOP_NUM_SCC] = NULL; @@ -256,7 +250,7 @@ void __init iop_preinit(void) } else { iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_QUADRA; } - iop_base[IOP_NUM_ISM]->status_ctrl = 0; + iop_stop(iop_base[IOP_NUM_ISM]); iop_ism_present = 1; } else { iop_base[IOP_NUM_ISM] = NULL;