| Message ID | 1587450467-19721-1-git-send-email-kuldeep.singh@nxp.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] spi: nxp-fspi: Add 1us delay to make controller ready for next transaction | expand |
On Tue, Apr 21, 2020 at 11:57 AM Kuldeep Singh <kuldeep.singh at nxp.com> wrote: > > Board gets reset when performing burst read/write operations. On the > other hand, no such behaviour is observed on small size operations. > > In Linux, readl_poll_timeout API already add delay of 1us which is > skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported version > of Linux driver and U-boot poll_timeout API lacks delay functionality, > add 1us delay so as to make controller ready for other transactions. Can you link me, where does Linux add this delay? Jagan.
> -----Original Message----- > From: Jagan Teki <jagan at amarulasolutions.com> > Sent: Tuesday, April 21, 2020 1:45 PM > To: Kuldeep Singh <kuldeep.singh at nxp.com> > Cc: U-Boot-Denx <u-boot at lists.denx.de> > Subject: [EXT] Re: [Patch v2] spi: nxp-fspi: Add 1us delay to make controller > ready for next transaction > > Caution: EXT Email > > On Tue, Apr 21, 2020 at 11:57 AM Kuldeep Singh <mailto:kuldeep.singh at nxp.com> > wrote: > > > > Board gets reset when performing burst read/write operations. On the > > other hand, no such behaviour is observed on small size operations. > > > > In Linux, readl_poll_timeout API already add delay of 1us which is > > skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported > > version of Linux driver and U-boot poll_timeout API lacks delay > > functionality, add 1us delay so as to make controller ready for other > transactions. > > Can you link me, where does Linux add this delay? Please see[1] for Linux nxp flexspi driver code. fspi_readl_poll_tout, line: 795 If you see implementation of " fspi_readl_poll_tout ", it further calls "readl_poll_timeout" which includes delay of 1us. And also please see the difference of "readl_poll_timeout" api implementation in uboot and Linux. This api adds delay in Linux but skips it in uboot. Thanks Kuldeep [1] https://elixir.bootlin.com/linux/latest/source/drivers/spi/spi-nxp-fspi.c
On Tue, Apr 21, 2020 at 2:56 PM Kuldeep Singh <kuldeep.singh at nxp.com> wrote: > > > > > -----Original Message----- > > From: Jagan Teki <jagan at amarulasolutions.com> > > Sent: Tuesday, April 21, 2020 1:45 PM > > To: Kuldeep Singh <kuldeep.singh at nxp.com> > > Cc: U-Boot-Denx <u-boot at lists.denx.de> > > Subject: [EXT] Re: [Patch v2] spi: nxp-fspi: Add 1us delay to make controller > > ready for next transaction > > > > Caution: EXT Email > > > > On Tue, Apr 21, 2020 at 11:57 AM Kuldeep Singh <mailto:kuldeep.singh at nxp.com> > > wrote: > > > > > > Board gets reset when performing burst read/write operations. On the > > > other hand, no such behaviour is observed on small size operations. > > > > > > In Linux, readl_poll_timeout API already add delay of 1us which is > > > skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported > > > version of Linux driver and U-boot poll_timeout API lacks delay > > > functionality, add 1us delay so as to make controller ready for other > > transactions. > > > > Can you link me, where does Linux add this delay? > > Please see[1] for Linux nxp flexspi driver code. > fspi_readl_poll_tout, line: 795 > > If you see implementation of " fspi_readl_poll_tout ", it further calls "readl_poll_timeout" which includes delay of 1us. > And also please see the difference of "readl_poll_timeout" api implementation in uboot and Linux. > This api adds delay in Linux but skips it in uboot. Yes, it worked for myself also. so please use the new api which I have introduced on this series [2] [2] https://patchwork.ozlabs.org/project/uboot/patch/20200425110354.12381-3-jagan at amarulasolutions.com/
> > If you see implementation of " fspi_readl_poll_tout ", it further calls > "readl_poll_timeout" which includes delay of 1us. > > And also please see the difference of "readl_poll_timeout" api > implementation in uboot and Linux. > > This api adds delay in Linux but skips it in uboot. > > Yes, it worked for myself also. so please use the new api which I have > introduced on this series [2] Thanks Jagan for the new API. I will respin this patch. -Kuldeep
diff --git a/drivers/spi/nxp_fspi.c b/drivers/spi/nxp_fspi.c index 0e6c7be..1c6538c 100644 --- a/drivers/spi/nxp_fspi.c +++ b/drivers/spi/nxp_fspi.c @@ -757,6 +757,13 @@ static int nxp_fspi_exec_op(struct spi_slave *slave, FSPI_STS0_ARB_IDLE, 1, POLL_TOUT, true); WARN_ON(err); + /* + * Watchdog gets triggered for large read/write/erase since this + * delay is not present in this API(readl_poll_timeout), add + * this delay here. + */ + udelay(1); + nxp_fspi_prepare_lut(f, op); /* * If we have large chunks of data, we read them through the AHB bus
Board gets reset when performing burst read/write operations. On the other hand, no such behaviour is observed on small size operations. In Linux, readl_poll_timeout API already add delay of 1us which is skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported version of Linux driver and U-boot poll_timeout API lacks delay functionality, add 1us delay so as to make controller ready for other transactions. Signed-off-by: Kuldeep Singh <kuldeep.singh at nxp.com> --- v1: Add comments above udelay(1) change. drivers/spi/nxp_fspi.c | 7 +++++++ 1 file changed, 7 insertions(+)