| Message ID | df8da322-6a42-642c-2c80-55fca0dab3ef@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Heiner Kallweit <hkallweit1@gmail.com> writes: > Remove use of unneeded members cmd_arg and cmd_resp. > Setting SD_EMMC_CMD_RSP is only needed if CMD_CFG_RESP_NUM is set, > so don't write this register in all other cases. > > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> I'm not sure I like this change. This works now because there is only one descriptor used, but one of the next things to work on in this driver is taking advantage of the internal DMA capabilities, which means having a chain of descriptorsall filled out in memory. Kevin > --- > drivers/mmc/host/meson-gx-mmc.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c > index ece38b44..630e0590 100644 > --- a/drivers/mmc/host/meson-gx-mmc.c > +++ b/drivers/mmc/host/meson-gx-mmc.c > @@ -456,7 +456,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) > desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) << > CMD_CFG_CMD_INDEX_SHIFT; > desc->cmd_cfg |= CMD_CFG_OWNER; /* owned by CPU */ > - desc->cmd_arg = cmd->arg; > > /* Response */ > if (cmd->flags & MMC_RSP_PRESENT) { > @@ -464,7 +463,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) > if (cmd->flags & MMC_RSP_136) > desc->cmd_cfg |= CMD_CFG_RESP_128; > desc->cmd_cfg |= CMD_CFG_RESP_NUM; > - desc->cmd_resp = 0; > + writel(0, host->regs + SD_EMMC_CMD_RSP); > > if (!(cmd->flags & MMC_RSP_CRC)) > desc->cmd_cfg |= CMD_CFG_RESP_NOCRC; > @@ -540,9 +539,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) > desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN; > writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG); > writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT); > - writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP); > wmb(); /* ensure descriptor is written before kicked */ > - writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG); > + writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); > } > > static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 15.02.2017 um 18:04 schrieb Kevin Hilman: > Heiner Kallweit <hkallweit1@gmail.com> writes: > >> Remove use of unneeded members cmd_arg and cmd_resp. >> Setting SD_EMMC_CMD_RSP is only needed if CMD_CFG_RESP_NUM is set, >> so don't write this register in all other cases. >> >> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > > I'm not sure I like this change. This works now because there is only > one descriptor used, but one of the next things to work on in this > driver is taking advantage of the internal DMA capabilities, which means > having a chain of descriptorsall filled out in memory. > For testing purposes I temporarily changed the driver from passing the descriptor in registers to passing the descriptor via DMA and it worked. I'm not very familiar (yet) with descriptor chains and have to check the MMC core code a little bit more .. If we can actually benefit from it then I'd agree with you. > Kevin > >> --- >> drivers/mmc/host/meson-gx-mmc.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c >> index ece38b44..630e0590 100644 >> --- a/drivers/mmc/host/meson-gx-mmc.c >> +++ b/drivers/mmc/host/meson-gx-mmc.c >> @@ -456,7 +456,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >> desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) << >> CMD_CFG_CMD_INDEX_SHIFT; >> desc->cmd_cfg |= CMD_CFG_OWNER; /* owned by CPU */ >> - desc->cmd_arg = cmd->arg; >> >> /* Response */ >> if (cmd->flags & MMC_RSP_PRESENT) { >> @@ -464,7 +463,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >> if (cmd->flags & MMC_RSP_136) >> desc->cmd_cfg |= CMD_CFG_RESP_128; >> desc->cmd_cfg |= CMD_CFG_RESP_NUM; >> - desc->cmd_resp = 0; >> + writel(0, host->regs + SD_EMMC_CMD_RSP); >> >> if (!(cmd->flags & MMC_RSP_CRC)) >> desc->cmd_cfg |= CMD_CFG_RESP_NOCRC; >> @@ -540,9 +539,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >> desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN; >> writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG); >> writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT); >> - writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP); >> wmb(); /* ensure descriptor is written before kicked */ >> - writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG); >> + writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); >> } >> >> static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 15.02.2017 um 20:43 schrieb Heiner Kallweit: > Am 15.02.2017 um 18:04 schrieb Kevin Hilman: >> Heiner Kallweit <hkallweit1@gmail.com> writes: >> >>> Remove use of unneeded members cmd_arg and cmd_resp. >>> Setting SD_EMMC_CMD_RSP is only needed if CMD_CFG_RESP_NUM is set, >>> so don't write this register in all other cases. >>> >>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> >> >> I'm not sure I like this change. This works now because there is only >> one descriptor used, but one of the next things to work on in this >> driver is taking advantage of the internal DMA capabilities, which means >> having a chain of descriptorsall filled out in memory. >> > For testing purposes I temporarily changed the driver from passing the > descriptor in registers to passing the descriptor via DMA and it worked. > > I'm not very familiar (yet) with descriptor chains and have to check > the MMC core code a little bit more .. > If we can actually benefit from it then I'd agree with you. > After having had a little bit closer look at the MMC core and descriptor chains in general: I'm not really sure where descriptor chains would help us. SG lists in read / write commands are linearized by the driver via sg_copy_[to,from]_buffer already. Beyond that I don't see any command chaining support in the core (prerequisite for command chaining most likely would be that a subsequent command must not depend on the response of a previous one). Maybe somebody with more knowledge about the MMC core and MMC in general can shed some light on this .. Heiner > >> Kevin >> >>> --- >>> drivers/mmc/host/meson-gx-mmc.c | 6 ++---- >>> 1 file changed, 2 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c >>> index ece38b44..630e0590 100644 >>> --- a/drivers/mmc/host/meson-gx-mmc.c >>> +++ b/drivers/mmc/host/meson-gx-mmc.c >>> @@ -456,7 +456,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >>> desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) << >>> CMD_CFG_CMD_INDEX_SHIFT; >>> desc->cmd_cfg |= CMD_CFG_OWNER; /* owned by CPU */ >>> - desc->cmd_arg = cmd->arg; >>> >>> /* Response */ >>> if (cmd->flags & MMC_RSP_PRESENT) { >>> @@ -464,7 +463,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >>> if (cmd->flags & MMC_RSP_136) >>> desc->cmd_cfg |= CMD_CFG_RESP_128; >>> desc->cmd_cfg |= CMD_CFG_RESP_NUM; >>> - desc->cmd_resp = 0; >>> + writel(0, host->regs + SD_EMMC_CMD_RSP); >>> >>> if (!(cmd->flags & MMC_RSP_CRC)) >>> desc->cmd_cfg |= CMD_CFG_RESP_NOCRC; >>> @@ -540,9 +539,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >>> desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN; >>> writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG); >>> writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT); >>> - writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP); >>> wmb(); /* ensure descriptor is written before kicked */ >>> - writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG); >>> + writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); >>> } >>> >>> static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) >> > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Heiner Kallweit <hkallweit1@gmail.com> writes: > Am 15.02.2017 um 20:43 schrieb Heiner Kallweit: >> Am 15.02.2017 um 18:04 schrieb Kevin Hilman: >>> Heiner Kallweit <hkallweit1@gmail.com> writes: >>> >>>> Remove use of unneeded members cmd_arg and cmd_resp. >>>> Setting SD_EMMC_CMD_RSP is only needed if CMD_CFG_RESP_NUM is set, >>>> so don't write this register in all other cases. >>>> >>>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> >>> >>> I'm not sure I like this change. This works now because there is only >>> one descriptor used, but one of the next things to work on in this >>> driver is taking advantage of the internal DMA capabilities, which means >>> having a chain of descriptorsall filled out in memory. >>> >> For testing purposes I temporarily changed the driver from passing the >> descriptor in registers to passing the descriptor via DMA and it worked. >> >> I'm not very familiar (yet) with descriptor chains and have to check >> the MMC core code a little bit more .. >> If we can actually benefit from it then I'd agree with you. >> > After having had a little bit closer look at the MMC core and descriptor > chains in general: > I'm not really sure where descriptor chains would help us. SG lists in > read / write commands are linearized by the driver via > sg_copy_[to,from]_buffer already. Copying to the bounce buffer would be replaced by creating a descriptor for each SG entry, and creating a descriptor chain. > Beyond that I don't see any command chaining support in the core > (prerequisite for command chaining most likely would be that a > subsequent command must not depend on the response of a previous one). > > Maybe somebody with more knowledge about the MMC core and MMC in general > can shed some light on this .. I don't know if it's a feature of the core, but the Amlogic vendor driver does the chained descriptor handling in the driver itself. Kevin >>> Kevin >>> >>>> --- >>>> drivers/mmc/host/meson-gx-mmc.c | 6 ++---- >>>> 1 file changed, 2 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c >>>> index ece38b44..630e0590 100644 >>>> --- a/drivers/mmc/host/meson-gx-mmc.c >>>> +++ b/drivers/mmc/host/meson-gx-mmc.c >>>> @@ -456,7 +456,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >>>> desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) << >>>> CMD_CFG_CMD_INDEX_SHIFT; >>>> desc->cmd_cfg |= CMD_CFG_OWNER; /* owned by CPU */ >>>> - desc->cmd_arg = cmd->arg; >>>> >>>> /* Response */ >>>> if (cmd->flags & MMC_RSP_PRESENT) { >>>> @@ -464,7 +463,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >>>> if (cmd->flags & MMC_RSP_136) >>>> desc->cmd_cfg |= CMD_CFG_RESP_128; >>>> desc->cmd_cfg |= CMD_CFG_RESP_NUM; >>>> - desc->cmd_resp = 0; >>>> + writel(0, host->regs + SD_EMMC_CMD_RSP); >>>> >>>> if (!(cmd->flags & MMC_RSP_CRC)) >>>> desc->cmd_cfg |= CMD_CFG_RESP_NOCRC; >>>> @@ -540,9 +539,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >>>> desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN; >>>> writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG); >>>> writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT); >>>> - writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP); >>>> wmb(); /* ensure descriptor is written before kicked */ >>>> - writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG); >>>> + writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); >>>> } >>>> >>>> static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) >>> >> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 15.02.2017 um 18:04 schrieb Kevin Hilman: > Heiner Kallweit <hkallweit1@gmail.com> writes: > >> Remove use of unneeded members cmd_arg and cmd_resp. >> Setting SD_EMMC_CMD_RSP is only needed if CMD_CFG_RESP_NUM is set, >> so don't write this register in all other cases. >> >> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > > I'm not sure I like this change. This works now because there is only > one descriptor used, but one of the next things to work on in this > driver is taking advantage of the internal DMA capabilities, which means > having a chain of descriptorsall filled out in memory. > I implemented the descriptor chain mode and tests (together with CMD23 mode) resulted in 140 MB/s read performance (from a 128GB eMMC card). So I will submit this extension together with the CMD23 mode extension. Heiner > Kevin > >> --- >> drivers/mmc/host/meson-gx-mmc.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c >> index ece38b44..630e0590 100644 >> --- a/drivers/mmc/host/meson-gx-mmc.c >> +++ b/drivers/mmc/host/meson-gx-mmc.c >> @@ -456,7 +456,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >> desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) << >> CMD_CFG_CMD_INDEX_SHIFT; >> desc->cmd_cfg |= CMD_CFG_OWNER; /* owned by CPU */ >> - desc->cmd_arg = cmd->arg; >> >> /* Response */ >> if (cmd->flags & MMC_RSP_PRESENT) { >> @@ -464,7 +463,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >> if (cmd->flags & MMC_RSP_136) >> desc->cmd_cfg |= CMD_CFG_RESP_128; >> desc->cmd_cfg |= CMD_CFG_RESP_NUM; >> - desc->cmd_resp = 0; >> + writel(0, host->regs + SD_EMMC_CMD_RSP); >> >> if (!(cmd->flags & MMC_RSP_CRC)) >> desc->cmd_cfg |= CMD_CFG_RESP_NOCRC; >> @@ -540,9 +539,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) >> desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN; >> writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG); >> writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT); >> - writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP); >> wmb(); /* ensure descriptor is written before kicked */ >> - writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG); >> + writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); >> } >> >> static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index ece38b44..630e0590 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -456,7 +456,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) << CMD_CFG_CMD_INDEX_SHIFT; desc->cmd_cfg |= CMD_CFG_OWNER; /* owned by CPU */ - desc->cmd_arg = cmd->arg; /* Response */ if (cmd->flags & MMC_RSP_PRESENT) { @@ -464,7 +463,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) if (cmd->flags & MMC_RSP_136) desc->cmd_cfg |= CMD_CFG_RESP_128; desc->cmd_cfg |= CMD_CFG_RESP_NUM; - desc->cmd_resp = 0; + writel(0, host->regs + SD_EMMC_CMD_RSP); if (!(cmd->flags & MMC_RSP_CRC)) desc->cmd_cfg |= CMD_CFG_RESP_NOCRC; @@ -540,9 +539,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN; writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG); writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT); - writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP); wmb(); /* ensure descriptor is written before kicked */ - writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG); + writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); } static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
Remove use of unneeded members cmd_arg and cmd_resp. Setting SD_EMMC_CMD_RSP is only needed if CMD_CFG_RESP_NUM is set, so don't write this register in all other cases. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/mmc/host/meson-gx-mmc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)