| Message ID | 20190610185354.35310-1-rrangel@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] mmc: sdhci: sdhci-pci-o2micro: Correctly set bus width when tuning | expand |
On 10/06/19 9:53 PM, Raul E Rangel wrote: > sdhci_send_tuning uses mmc->ios.bus_width to determine the block size. > Without this patch the block size would be set incorrectly when the > bus_width == 8 which results in tuning failing. > > Signed-off-by: Raul E Rangel <rrangel@chromium.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> > --- > > drivers/mmc/host/sdhci-pci-o2micro.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c > index b29bf4e7dcb48..dd21315922c87 100644 > --- a/drivers/mmc/host/sdhci-pci-o2micro.c > +++ b/drivers/mmc/host/sdhci-pci-o2micro.c > @@ -115,6 +115,7 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > */ > if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { > current_bus_width = mmc->ios.bus_width; > + mmc->ios.bus_width = MMC_BUS_WIDTH_4; > sdhci_set_bus_width(host, MMC_BUS_WIDTH_4); > } > > @@ -126,8 +127,10 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > > sdhci_end_tuning(host); > > - if (current_bus_width == MMC_BUS_WIDTH_8) > + if (current_bus_width == MMC_BUS_WIDTH_8) { > + mmc->ios.bus_width = MMC_BUS_WIDTH_8; > sdhci_set_bus_width(host, current_bus_width); > + } > > host->flags &= ~SDHCI_HS400_TUNING; > return 0; >
On Mon, 10 Jun 2019 at 20:54, Raul E Rangel <rrangel@chromium.org> wrote: > > sdhci_send_tuning uses mmc->ios.bus_width to determine the block size. > Without this patch the block size would be set incorrectly when the > bus_width == 8 which results in tuning failing. > > Signed-off-by: Raul E Rangel <rrangel@chromium.org> > --- > > drivers/mmc/host/sdhci-pci-o2micro.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c > index b29bf4e7dcb48..dd21315922c87 100644 > --- a/drivers/mmc/host/sdhci-pci-o2micro.c > +++ b/drivers/mmc/host/sdhci-pci-o2micro.c > @@ -115,6 +115,7 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > */ > if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { > current_bus_width = mmc->ios.bus_width; > + mmc->ios.bus_width = MMC_BUS_WIDTH_4; This looks wrong. mmc->ios.bus_width is not supposed to be updated by a host driver, but rather the value should only be read. > sdhci_set_bus_width(host, MMC_BUS_WIDTH_4); > } > > @@ -126,8 +127,10 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > > sdhci_end_tuning(host); > > - if (current_bus_width == MMC_BUS_WIDTH_8) > + if (current_bus_width == MMC_BUS_WIDTH_8) { > + mmc->ios.bus_width = MMC_BUS_WIDTH_8; Ditto. > sdhci_set_bus_width(host, current_bus_width); > + } > > host->flags &= ~SDHCI_HS400_TUNING; > return 0; > -- > 2.22.0.rc2.383.gf4fbbf30c2-goog > Kind regards Uffe
On Wed, Jun 12, 2019 at 03:36:25PM +0200, Ulf Hansson wrote: > On Mon, 10 Jun 2019 at 20:54, Raul E Rangel <rrangel@chromium.org> wrote: > > > > sdhci_send_tuning uses mmc->ios.bus_width to determine the block size. > > Without this patch the block size would be set incorrectly when the > > bus_width == 8 which results in tuning failing. > > > > Signed-off-by: Raul E Rangel <rrangel@chromium.org> > > --- > > > > drivers/mmc/host/sdhci-pci-o2micro.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c > > index b29bf4e7dcb48..dd21315922c87 100644 > > --- a/drivers/mmc/host/sdhci-pci-o2micro.c > > +++ b/drivers/mmc/host/sdhci-pci-o2micro.c > > @@ -115,6 +115,7 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > > */ > > if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { > > current_bus_width = mmc->ios.bus_width; > > + mmc->ios.bus_width = MMC_BUS_WIDTH_4; > > This looks wrong. > > mmc->ios.bus_width is not supposed to be updated by a host driver, but I guess I left this part out: The O2Micro controller only supports tuning at 4-bits. So the host driver needs to change the bus width while tuning and then set it back when done. Ideally I would have used `mmc_set_bus_width()`, but that is a core only function. If `sdhci_send_tuning()` didn't rely on mmc->ios.bus_width to determine the bus width, but instead read the HOST_CONTROL register then this patch wouldn't be needed. > rather the value should only be read. > > > sdhci_set_bus_width(host, MMC_BUS_WIDTH_4); > > } > > > > @@ -126,8 +127,10 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > > > > sdhci_end_tuning(host); > > > > - if (current_bus_width == MMC_BUS_WIDTH_8) > > + if (current_bus_width == MMC_BUS_WIDTH_8) { > > + mmc->ios.bus_width = MMC_BUS_WIDTH_8; > > Ditto. > > > sdhci_set_bus_width(host, current_bus_width); > > + } > > > > host->flags &= ~SDHCI_HS400_TUNING; > > return 0; > > -- > > 2.22.0.rc2.383.gf4fbbf30c2-goog > > > > Kind regards > Uffe Thanks for the review!
On Wed, 12 Jun 2019 at 17:01, Raul Rangel <rrangel@chromium.org> wrote: > > On Wed, Jun 12, 2019 at 03:36:25PM +0200, Ulf Hansson wrote: > > On Mon, 10 Jun 2019 at 20:54, Raul E Rangel <rrangel@chromium.org> wrote: > > > > > > sdhci_send_tuning uses mmc->ios.bus_width to determine the block size. > > > Without this patch the block size would be set incorrectly when the > > > bus_width == 8 which results in tuning failing. > > > > > > Signed-off-by: Raul E Rangel <rrangel@chromium.org> > > > --- > > > > > > drivers/mmc/host/sdhci-pci-o2micro.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c > > > index b29bf4e7dcb48..dd21315922c87 100644 > > > --- a/drivers/mmc/host/sdhci-pci-o2micro.c > > > +++ b/drivers/mmc/host/sdhci-pci-o2micro.c > > > @@ -115,6 +115,7 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > > > */ > > > if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { > > > current_bus_width = mmc->ios.bus_width; > > > + mmc->ios.bus_width = MMC_BUS_WIDTH_4; > > > > This looks wrong. > > > > mmc->ios.bus_width is not supposed to be updated by a host driver, but > I guess I left this part out: The O2Micro controller only supports > tuning at 4-bits. So the host driver needs to change the bus width while > tuning and then set it back when done. Thanks for clarifying. Please add that information to the changelog and a minor comment in the code as well. > Ideally I would have used > `mmc_set_bus_width()`, but that is a core only function. Well, that function also calls mmc_set_ios(), which is not what you want, or is it? > > If `sdhci_send_tuning()` didn't rely on mmc->ios.bus_width to determine > the bus width, but instead read the HOST_CONTROL register then this > patch wouldn't be needed. Could you elaborate on that. Perhaps there are variants that have a similar constraint and in such case, this solution could possibly help them as well. > > rather the value should only be read. > > > > > sdhci_set_bus_width(host, MMC_BUS_WIDTH_4); > > > } > > > > > > @@ -126,8 +127,10 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) > > > > > > sdhci_end_tuning(host); > > > > > > - if (current_bus_width == MMC_BUS_WIDTH_8) > > > + if (current_bus_width == MMC_BUS_WIDTH_8) { > > > + mmc->ios.bus_width = MMC_BUS_WIDTH_8; > > > > Ditto. > > > > > sdhci_set_bus_width(host, current_bus_width); > > > + } > > > > > > host->flags &= ~SDHCI_HS400_TUNING; > > > return 0; > > > -- > > > 2.22.0.rc2.383.gf4fbbf30c2-goog > > > > > Kind regards Uffe
diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c index b29bf4e7dcb48..dd21315922c87 100644 --- a/drivers/mmc/host/sdhci-pci-o2micro.c +++ b/drivers/mmc/host/sdhci-pci-o2micro.c @@ -115,6 +115,7 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) */ if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { current_bus_width = mmc->ios.bus_width; + mmc->ios.bus_width = MMC_BUS_WIDTH_4; sdhci_set_bus_width(host, MMC_BUS_WIDTH_4); } @@ -126,8 +127,10 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) sdhci_end_tuning(host); - if (current_bus_width == MMC_BUS_WIDTH_8) + if (current_bus_width == MMC_BUS_WIDTH_8) { + mmc->ios.bus_width = MMC_BUS_WIDTH_8; sdhci_set_bus_width(host, current_bus_width); + } host->flags &= ~SDHCI_HS400_TUNING; return 0;
sdhci_send_tuning uses mmc->ios.bus_width to determine the block size. Without this patch the block size would be set incorrectly when the bus_width == 8 which results in tuning failing. Signed-off-by: Raul E Rangel <rrangel@chromium.org> --- drivers/mmc/host/sdhci-pci-o2micro.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)