Message ID | 17913d2dea0200f818af5f42a0b2ed42@walle.cc (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Am 14.11.2016 um 15:22 schrieb Michael Walle: > Hi, > > since commit 02a595d5d6e4 (spi: fsl-espi: eliminate spi nor flash read loop) the fsl-espi is (partly?) broken. Reading 64k from the flash results in the following error: > fsl_espi ffe110000.spi: message too long, size is 65540 bytes > spi_master spi32766: failed to transfer one message from queue > > We are using the m25p80 driver which checks the max_transfer_size. The fsl-espi driver sets the max_message_size to 64k. As far as I understand it, a message can contain multiple transfers. The m25p80 uses two transfers (one 4 byte and one with max_transfer_size, that is 64k) and thus the message has a total length of 65540 bytes which is too long for the driver. > > I didn't find where the max_message_size is checked and I also don't know which part is resposible to handle the correct sizes. The m25p80 driver? Should it use spi_max_message_size() instead of spi_max_transfer_size() ? > Your mail actually doesn't come as a surprise. The patch addressing this scenario is waiting to be applied. See here: https://www.spinics.net/lists/linux-spi/msg08844.html Rgds, Heiner > For example: > --- a/drivers/mtd/devices/m25p80.c > +++ b/drivers/mtd/devices/m25p80.c > @@ -172,7 +172,7 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len, > > t[1].rx_buf = buf; > t[1].rx_nbits = m25p80_rx_nbits(nor); > - t[1].len = min(len, spi_max_transfer_size(spi) - t[0].len); > + t[1].len = min(len, spi_max_message_size(spi) - t[0].len); > spi_message_add_tail(&t[1], &m); > > ret = spi_sync(spi, &m); > > -michael > -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 2016-11-14 20:06, schrieb Heiner Kallweit: > Am 14.11.2016 um 15:22 schrieb Michael Walle: >> Hi, >> >> since commit 02a595d5d6e4 (spi: fsl-espi: eliminate spi nor flash read >> loop) the fsl-espi is (partly?) broken. Reading 64k from the flash >> results in the following error: >> fsl_espi ffe110000.spi: message too long, size is 65540 bytes >> spi_master spi32766: failed to transfer one message from queue >> >> We are using the m25p80 driver which checks the max_transfer_size. The >> fsl-espi driver sets the max_message_size to 64k. As far as I >> understand it, a message can contain multiple transfers. The m25p80 >> uses two transfers (one 4 byte and one with max_transfer_size, that is >> 64k) and thus the message has a total length of 65540 bytes which is >> too long for the driver. >> >> I didn't find where the max_message_size is checked and I also don't >> know which part is resposible to handle the correct sizes. The m25p80 >> driver? Should it use spi_max_message_size() instead of >> spi_max_transfer_size() ? >> > Your mail actually doesn't come as a surprise. The patch addressing > this scenario is waiting to be applied. > See here: https://www.spinics.net/lists/linux-spi/msg08844.html > > Rgds, Heiner Thanks. -michael -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 14.11.2016 um 20:06 schrieb Heiner Kallweit: > Am 14.11.2016 um 15:22 schrieb Michael Walle: >> Hi, >> >> since commit 02a595d5d6e4 (spi: fsl-espi: eliminate spi nor flash read loop) the fsl-espi is (partly?) broken. Reading 64k from the flash results in the following error: >> fsl_espi ffe110000.spi: message too long, size is 65540 bytes >> spi_master spi32766: failed to transfer one message from queue >> >> We are using the m25p80 driver which checks the max_transfer_size. The fsl-espi driver sets the max_message_size to 64k. As far as I understand it, a message can contain multiple transfers. The m25p80 uses two transfers (one 4 byte and one with max_transfer_size, that is 64k) and thus the message has a total length of 65540 bytes which is too long for the driver. >> >> I didn't find where the max_message_size is checked and I also don't know which part is resposible to handle the correct sizes. The m25p80 driver? Should it use spi_max_message_size() instead of spi_max_transfer_size() ? >> > Your mail actually doesn't come as a surprise. The patch addressing this scenario is waiting to be applied. > See here: https://www.spinics.net/lists/linux-spi/msg08844.html > > Rgds, Heiner > This issue is still open. Can we get the patch at least into 4.10? -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi all, Le 14/11/2016 à 15:22, Michael Walle a écrit : > Hi, > > since commit 02a595d5d6e4 (spi: fsl-espi: eliminate spi nor flash read > loop) the fsl-espi is (partly?) broken. Reading 64k from the flash results > in the following error: > fsl_espi ffe110000.spi: message too long, size is 65540 bytes > spi_master spi32766: failed to transfer one message from queue > > We are using the m25p80 driver which checks the max_transfer_size. The > fsl-espi driver sets the max_message_size to 64k. As far as I understand > it, a message can contain multiple transfers. The m25p80 uses two transfers > (one 4 byte and one with max_transfer_size, that is 64k) and thus the > message has a total length of 65540 bytes which is too long for the driver. > > I didn't find where the max_message_size is checked and I also don't know > which part is resposible to handle the correct sizes. The m25p80 driver? > Should it use spi_max_message_size() instead of spi_max_transfer_size() ? > > For example: > --- a/drivers/mtd/devices/m25p80.c > +++ b/drivers/mtd/devices/m25p80.c > @@ -172,7 +172,7 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t > from, size_t len, > > t[1].rx_buf = buf; > t[1].rx_nbits = m25p80_rx_nbits(nor); > - t[1].len = min(len, spi_max_transfer_size(spi) - t[0].len); > + t[1].len = min(len, spi_max_message_size(spi) - t[0].len); > spi_message_add_tail(&t[1], &m); > extracted from include/linux/spi/spi:h: static inline size_t spi_max_transfer_size(struct spi_device *spi) { struct spi_master *master = spi->master; size_t tr_max = SIZE_MAX; size_t msg_max = spi_max_message_size(spi); if (master->max_transfer_size) tr_max = master->max_transfer_size(spi); /* transfer size limit must not be greater than messsage size limit */ return min(tr_max, msg_max); } So replacing spi_max_transfer_size(spi) by spi_max_transfer_size(spi) is not a good idea: the max transfer size is always lower than or equal to the max message size. However taking the min between: 1/ len 2/ spi_max_transfer_size(spi) 3/ spi_max_message_size(spi) - t[0].len /* the remaining msg size */ makes sense. Hence https://www.spinics.net/lists/linux-spi/msg08844.html seems to be the right solution. Best regards, Cyrille > ret = spi_sync(spi, &m); > > -michael > -- > To unsubscribe from this list: send the line "unsubscribe linux-spi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -172,7 +172,7 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len, t[1].rx_buf = buf; t[1].rx_nbits = m25p80_rx_nbits(nor); - t[1].len = min(len, spi_max_transfer_size(spi) - t[0].len); + t[1].len = min(len, spi_max_message_size(spi) - t[0].len); spi_message_add_tail(&t[1], &m);