| Message ID | 20110621020913.GE16230@verge.net.au (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hey Simon, On Tue, Jun 21, 2011 at 11:09 AM, Simon Horman <horms@verge.net.au> wrote: > On Tue, Jun 21, 2011 at 10:36:05AM +0900, Magnus Damm wrote: >> On Tue, Jun 21, 2011 at 10:13 AM, Simon Horman <horms@verge.net.au> wrote: >> > On Tue, Jun 21, 2011 at 09:59:37AM +0900, Magnus Damm wrote: >> >> On Tue, Jun 21, 2011 at 9:50 AM, Simon Horman <horms@verge.net.au> wrote: >> >> > On Tue, Jun 21, 2011 at 09:36:03AM +0900, Magnus Damm wrote: >> >> >> On Tue, Jun 21, 2011 at 8:00 AM, Simon Horman <horms@verge.net.au> wrote: >> > >> > [snip] >> > >> >> >> > index 5a90266..0dc9804 100644 >> >> >> > --- a/include/linux/mfd/tmio.h >> >> >> > +++ b/include/linux/mfd/tmio.h >> >> >> > @@ -94,6 +101,7 @@ struct tmio_mmc_data { >> >> >> > void (*set_pwr)(struct platform_device *host, int state); >> >> >> > void (*set_clk_div)(struct platform_device *host, int state); >> >> >> > int (*get_cd)(struct platform_device *host); >> >> >> > + int (*write16_hook)(struct tmio_mmc_host *host, int addr); >> >> >> > }; >> >> >> > >> >> >> > static inline void tmio_mmc_cd_wakeup(struct tmio_mmc_data *pdata) >> >> >> >> >> >> What's the reason behind passing "struct tmio_mmc_host *" as an >> >> >> argument to the new hook? Performance? All other callbacks seem to >> >> >> take a "struct platform_device *", so being consistent here may be >> >> >> good unless it comes with too much overhead. >> >> > >> >> > The reason is that >> >> > 1) The hook is called from sd_ctrl_write16 which takes >> >> > struct tmio_mmc_host * as its first argument and; >> >> > 2) The hook that has been implemented calls sd_ctrl_read16() which takes a >> >> > struct tmio_mmc_host * as its first argument. >> >> > So it seemed logical to pass that down. >> >> > >> >> > In the caes of 1) we can get the struct platform_device * using host->pdev. >> >> > However, in the case of 2) is it less clear to me how we can get the >> >> > struct tmio_mmc_host * from a struct platform_device *. >> >> >> >> Have a look at the code in tmio_mmc_host_suspend() for some code that >> >> does struct device * -> struct tmio_mmc_host *: >> >> int tmio_mmc_host_suspend(struct device *dev) >> >> { >> >> struct mmc_host *mmc = dev_get_drvdata(dev); >> >> struct tmio_mmc_host *host = mmc_priv(mmc); >> >> >> >> You can easily change the dev_get_drvdata() to platform_get_drvdata(), >> >> see include/linux/platform_device.h >> > >> > Thanks, I'm happy to make that change if you think it is worth it. >> > (I will need to re-test on AG5, which I could do this afternoon >> > if it is free) >> >> Hm, perhaps it can be done with incremental patches in the future? >> >> I think it's good to be consistent and use the same argument passing >> style as other callbacks, but at the same time I'm not 100% sure if >> passing a platform data pointer is the best approach. It probably made >> sense with the old tmio_mmc driver that only hooked up to MFD, but I'm >> not sure if that's the case anymore. I'm sure there is room for plenty >> of cleanups - but exactly what to do I don't know. =) >> >> At least passing a struct tmio_mmc_host * requires little conversion >> which should add minimal overhead. > > Ok, lets stick with what we have for now. > Its a fairly trivial change to update the arguments later > if that is wanted. Testing is slightly less trivial > due to availability of hardware, but not a major problem. > > Can you Acked-by, or Reviewed-by the patches in this series if > you are now happy with them? Sure, for all patches included in this series: Acked-by: Magnus Damm <damm@opensource.se> >> >> I guess a similar conversion can be done in tmio_mmc_enable_dma() to >> >> move from writew() to sd_ctrl_write16()? >> > >> > Are you proposing changing tmio_mmc_enable_dma() to take >> > a struct platform_device * as its first argument? >> >> No, not at all. I just recall someone pointing out that >> tmio_mmc_enable_dma() skipped the tmio_mmc specific I/O routines and >> used writew() directly. I suspected the reason behind this was the >> difficulty of converting between different pointer types, but that may >> not be true. > > I was probably the person who pointed that out to you. > I'm unsure of the reason, but at least in its current form > it appears not to be related to the parameters involved. Yeah. Probably me being confused of which patches that modify which functions. =) >> > tmio_mmc_enable_dma() is already altered in one of the >> > patches in this series to use sd_ctrl_write16() without >> > altering the arguments taht tmio_mmc_enable_dma() takes. >> >> Ok, that's good. >> >> > static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable) >> > { >> > #if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE) >> > /* Switch DMA mode on or off - SuperH specific? */ >> > sd_ctrl_write16(host, enable ? 2 : 0, CTL_DMA_ENABLE); >> > #endif >> > } >> >> Hm, perhaps it's my mail setup that's the issue, but the version of >> "[PATCH 1/5] mmc: tmio: name 0xd8 as CTL_DMA_ENABLE" that I'm looking >> at is still using writew(). > > The writew() -> sd_ctrl_write16() change is made by the following patch > in the series, "[PATCH 2/5] mmc: tmio: Share register access functions". > > The last hunk looks like this: > > diff --git a/drivers/mmc/host/tmio_mmc_dma.c > b/drivers/mmc/host/tmio_mmc_dma.c > index 9c4da66..f24a029 100644 > --- a/drivers/mmc/host/tmio_mmc_dma.c > +++ b/drivers/mmc/host/tmio_mmc_dma.c > @@ -26,7 +26,7 @@ static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable) > { > #if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE) > /* Switch DMA mode on or off - SuperH specific? */ > - writew(enable ? 2 : 0, host->ctl + (CTL_DMA_ENABLE << host->bus_shift)); > + sd_ctrl_write16(host, enable ? 2 : 0, CTL_DMA_ENABLE); > #endif > } Gotcha. Looking good, thank you! / magnus -- 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/tmio_mmc_dma.c b/drivers/mmc/host/tmio_mmc_dma.c index 9c4da66..f24a029 100644 --- a/drivers/mmc/host/tmio_mmc_dma.c +++ b/drivers/mmc/host/tmio_mmc_dma.c @@ -26,7 +26,7 @@ static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable) { #if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE) /* Switch DMA mode on or off - SuperH specific? */ - writew(enable ? 2 : 0, host->ctl + (CTL_DMA_ENABLE << host->bus_shift)); + sd_ctrl_write16(host, enable ? 2 : 0, CTL_DMA_ENABLE); #endif }