On Fri, 30 Nov 2018 11:19:03 +0200 Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: > Commands and resets are under spin lock, so no possibility for > preemption, and certainly a few microseconds isn't going to make any > difference to these timeouts, so I don't see how this patch could > help. Thanks for your review. I believe my case the scheduling out delay sometime can reach 10~20 milliseconds... This may be due to the hypervisor... Please look at the sdhci_enable_clk() below, there is a window in clock stabilization check. The first check is to check status register, the second check is to check if time passed. That's why I can capture a case that after time passed, the actually clock control register indicated that clock is stable. So the error handling is wrong... Also the sdhci_send_command commands is not in spin lock There is a windows between mod_timer and real command send... Thanks, Alek > > I recently sent a patch for GLK laptops that had BIOS issues: > > https://marc.info/?l=linux-mmc&m=154270005901609 > > And also some improvements to error handling: > > https://marc.info/?l=linux-mmc&m=154229013900437 > > If those don't help, please share more details of the actual problem. Sorry, I can't see how this patches could fix my problem. > > > > > Signed-off-by: Alek Du <alek.du@xxxxxxxxx> > > --- > > drivers/mmc/host/sdhci.c | 19 ++++++++++++++++--- > > 1 file changed, 16 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > > index 99bdae53fa2e..f88c49fc574e 100644 > > --- a/drivers/mmc/host/sdhci.c > > +++ b/drivers/mmc/host/sdhci.c > > @@ -218,12 +218,17 @@ void sdhci_reset(struct sdhci_host *host, u8 > > mask) /* hw clears the bit when it's done */ > > while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) { > > if (ktime_after(ktime_get(), timeout)) { > > + /* check it again, since there is a window > > between > > + bit check and time check */ > > + if (!(sdhci_readb(host, > > SDHCI_SOFTWARE_RESET) & mask)) > > + break; > > pr_err("%s: Reset 0x%x never completed.\n", > > mmc_hostname(host->mmc), > > (int)mask); sdhci_dumpregs(host); > > return; > > + } else { > > + udelay(10); > > } > > - udelay(10); > > } > > } > > EXPORT_SYMBOL_GPL(sdhci_reset); > > @@ -1395,9 +1400,10 @@ void sdhci_send_command(struct sdhci_host > > *host, struct mmc_command *cmd) timeout += > > DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ; else > > timeout += 10 * HZ; > > - sdhci_mod_timer(host, cmd->mrq, timeout); > > > > sdhci_writew(host, SDHCI_MAKE_CMD(cmd->opcode, flags), > > SDHCI_COMMAND); > > + /* setup timer after command to avoid fake timeout */ > > + sdhci_mod_timer(host, cmd->mrq, timeout); > > } > > EXPORT_SYMBOL_GPL(sdhci_send_command); > > > > @@ -1611,12 +1617,19 @@ void sdhci_enable_clk(struct sdhci_host > > *host, u16 clk) while (!((clk = sdhci_readw(host, > > SDHCI_CLOCK_CONTROL)) & SDHCI_CLOCK_INT_STABLE)) { > > if (ktime_after(ktime_get(), timeout)) { > > + /* check it again since there is a window > > between > > + status check and time check */ > > + if ((clk = sdhci_readw(host, > > SDHCI_CLOCK_CONTROL)) > > + & SDHCI_CLOCK_INT_STABLE) > > + break; > > pr_err("%s: Internal clock never > > stabilised.\n", mmc_hostname(host->mmc)); > > sdhci_dumpregs(host); > > return; > > } > > - udelay(10); > > + else { > > + udelay(10); > > + } > > } > > > > clk |= SDHCI_CLOCK_CARD_EN; > > >
